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Bitcoin / Block chain explanation video? /r/Bitcoin

Bitcoin / Block chain explanation video? /Bitcoin submitted by BitcoinAllBot to BitcoinAll [link] [comments]

[OWL WATCH] Waiting for "IOTA TIME" 14;

Disclaimer: This is my editing, so there could be some errors, misunderstandings or exaggerations.
Waiting for "IOTA TIME " (an era where IOTA defines nearly everything in terms of the block-chain world)

niels12어제 오후 4:51
IOTA funds are public: https://thetangle.org/address/IDNAFP9FWWKYGNDMKGJWZD9GATGRPTJYTYHLKFNDEQSISPSETLZQOSPGOHC99LMPXDEHSH9XYHNVOLUBBQPCEGHYK9 But they have probably other sources of income, like funding by government etc. And maybe also other IOTA funds on other addresses. I don't know.
Balance: 59.68 Ti


David Sønstebø어제 오후 9:41
I wonder how many times an out of context 2 year old private DM has to be addressed. At the time IOTA was approaching stagnation due to the actions of primarily CFB**, thus since we both started Jinn together which lead to IOTA,** I tried repeatedly to talk sense into him. I.E. "If you are going to torpedo all progress, let's just sell it all and start from scratch, fuck it" It's a figure of speech, while trying to talk sense into someone who insists that 1 + 1 = 3.59 My tax records show when I last sold iotas. February of 2018. Now stop reading into private DMs, especially ones taken out of context and especially those leaked by someone who's proclaimed he is going to ruin IOTA and my life. You need to go back to school if you think there is anything to 'speculate' on there.


dom어제 오후 4:15
u/unsy we will release the condensed version of them once we want to. Just because you so desperately desire them for whatever reason doesn't make us do it faster. Being in this space for so fucking long, last thing I want is to attempt to act in good faith again and then be screwed over by those trying to misconstrue reality and spread lies. We've been at that for too long. Once they are fully ready, and we have them in a format we like, we will publish them.


dom어제 오후 4:16
Our objective of the finance / legal department is to become one of the most trustworthy / transparent organizations in this space. Which is why we're setting up new and stricter policies in general


dom어제 오후 4:18
quite frankly, with everything that has happened up until now, I would certainly say that we are one of the most transparent organization (if we wanted it or not) u/unsy


dom어제 오후 4:21
u/unsy I am not worried about it. If we have problems, we always solve them - I think we've proven that by now. And as it stands right now with our current funding + our strategy, we are in good hands


David Sønstebø오늘 오전 6:41
Don't worry, a shitty FUD piece in a cryptoblog is nada
[오전 6:41]
We were once numero uno target by Jeffrey Epstein funded Joi Ito's MIT DCI
[오전 6:41]
This is nothing


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Antonio Nardella [IF]어제 오후 11:13
IMO the community has matured a lot, we have community and certified developers working with the IF in the X-Teams, there are new people coming in with direct interest in the tech (yeah, also spec is still popular) and from the chats that I've had, there are devs waiting for the breaking changes of Chrysalis P2, before starting to develop again.. But that's my assessment..


Jelle Millenaar [IF]어제 오후 9:15
Well, I can say the DID developments are going smooth. Starting publishing the first DIDs to the Tangle ;D


Jelle Millenaar [IF]어제 오후 9:15
And since I am totally not biased towards Identity, but its gonna be revolutionary ;D


Jelle Millenaar [IF]어제 오후 10:06
This is the perfect time to loose faith in the IOTA Foundations capability to deliver, especially after the network just received a major update with many improvements. Its just crypto being crypto,


dom오늘 오전 2:12
Yeh we'll go through it. This is the usual game...


Dominik Schiener
There is more tech maturity, more adoption and more progress than ever. We are one of the only projects which gets funding from government grants and corporations. Stop the attention grabbing headlines and get your sources right.


Long field
You can track their iota address, and I can tell they didn't sell any iota tokens in last two months


HusQy
IOTA is like a large decentralized network cable that connects any number of nodes with each other and that enables data and values ​​to be exchanged with one another, whereby the data is protected against manipulation and the value transactions against double spends. Thereon ...

... you can run any decentralized application (we call this layer) - e.g. a blockchain that stores certain data for as long as you want and limits the amount of data to be saved via fees like Bitcoin. Each of these uses inherit ...

... your security from the basic protocol and can specifically only save the data that is relevant for you (also decentralized). To say that IOTA is not a DLT is in principle not that wrong - it is a platform for DLTs and therefore much more powerful than all ...

... existing DLTs because it is much more flexible. For example, you can run Hashgraph in IOTA, or Bitcoin or whatever. And IOTA is the token that connects the entire ecosystem. This is of course "not yet" the case, but Chrysalis Part 2 is the first step.​


HusQy
@blocktrainerperhaps this explanation will enable you to understand where the journey is going. If a decentralized data storage is required, then you can build it with IOTA and it then has exactly the same properties in terms of permanent storage as Bitcoin.


Block trainer
We can also get a little more technical. The way you describe it, it sounds like an interoperability layer ... something like that here, which then equates to a polkadot etc.
📷

HusQy
In principle yes, only that it doesn't connect Bitcoin and ETH but "IOTA Smart Contracts" with "IOTA Storage" etc. It is not there to connect other projects but to offer the same as other projects, only faster and cheaper.

-------------------------------------------------------------------------------

Bitcoin Coach
And in 5 years there will be a completely new project, which then claims to be better than IOTA. And then should all the infrastructure be thrown overboard and the partners simply change the DLT?


HusQy
This is how technology works. It makes no sense to run the Internet on the basis of 64k modems just because many people have one at home. The change does not take place overnight but creeping and if you look at the BTC Dominance you can see that too.

Ultimately, everything will switch to the best technology and we'll see which that is :)


Block trainer
The "best" must also be defined. What are the classes to master?


HusQy
All classes. If there is a technology that can represent even one aspect better, then it is not yet good enough. Blockchain, for example, is a "degenerate" DAG with only one reference. The goal is that IOTA can also use blockchains if the use case requires it.


HusQy
The future is not "either DAG or blockchain" but both seamlessly linked within the same ecosystem. IOTA smart contracts use a blockchain, for example, but a separate chain for each smart contract and the blockchain is within the tangle.

Block trainer
According to the new definition, they are no longer saved ... A doublespent could change the reference retrospectively.


HusQy
That's not quite true. The tangle itself contains all information for all eternity and you cannot remove any information. Once the data has reached a certain age, it is no longer stored by every node in the network. But you can still ...

... still prove what happened in the part of the tangle that was "forgotten" by the nodes after a certain time. Now there are two ways to keep this evidence: 1. You save the evidence personally and can present it at any time. 2. Man ...​​

... writes a plug-in for the node, which monitors the Tangle for information of a certain type and keeps a copy of all car purchase-related data forever (or for at least 30 years, for example). All dealerships could then install this plugin and ...

... jointly store this data decentrally in order to query the information if necessary. However, you would only selectively save the data that interests you. The evidence they produce can still be verified by any node on the network.​​

If the server of a car dealership fails, it can download the data again from one of the other dealerships. Quasi like an application-related private blockchain which is secured by the Tangle. It is also conceivable that there are service providers for this ...

----------------------------------------------------------------------------------


HusQy
Data is only kept immutable. How do you intend to execute a token transaction over pure data? I'm simply sending the following two data transactions at the same time: 1. I'm sending $ 100 from address A to address B. 2. I'm sending $ 100 from address A to address C.


HusQy
In order to determine which transaction is successful / came first, you need consensus. Data transactions do not allow token transfer.


Block trainer
Why doesn't that allow token transfer? I can simply use it to sign my values. The question is about the meaning of the token. I can also sign that I have transferred € 10 for the petrol station. Or I transmit the proof via curled BTC ...


HusQy
Did I just describe you can publish two conflicting data transactions and no one knows which is the correct one: P


Block trainer
Unless you agree on a consensus. Time stamp + BTC (locked) in hash = value transmitted ... What else is the IOTA token for?


HusQy
Whether information is correct can only be seen in the context. Take a look at the difference between "data" and "information". For example, you can claim that you locked Bitcoin even though it didn't.


Block trainer
I may need a proof of this. See how, for example, BTC is unlocked in liquid or in the LN. The IOTA data layer is extremely similar to the principle of Lightning. Accordingly, the sending of tokens would be possible here, which means that I see the use case of the IOTA coin at risk


HusQy
Such a proof is impossible. The reason why this works with LN nodes is because LN nodes are Bitcoin nodes that know what is happening in the Bitcoin network and have "information" and not just "data": P What you are describing is technically impossible.


Block trainer
Data = information What can the LN not, what IOTA can sometimes?


HusQy
That's not rubbish. There is a huge difference between data and information, and inter-chain transactions are not possible because of that very difference. LN won't work - there are too many game theory problems: P​

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Dominik Schiener
There is more tech maturity, more adoption and more progress than ever. We are one of the only projects which gets funding from government grants and corporations. Stop the attention grabbing headlines and get your sources right.


Dominik Schiener
As an innovation leader in Europe, I certainly say we deserve to get grants. There is a below 7% success chance usually. And yes, everything is fully audited (by externals ofc), showing clearly how and that the money was used in achieving the milestones of the grant.

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6 Reasons Why Serum Won't Succeed

6 Reasons Why Serum Won't Succeed

The world of DeFi is exploding but is it all it’s made out to be?

DeFi (decentralised finance) is most certainly the buzz in the crypto world this minute. It’s bringing similar feelings which was the 2017/18 ICO phase, where a mammoth of new projects begun to explode onto the scene, each with their own promise of new innovation and use case.
Hindsight has shown us that most of those projects have ultimately failed, or worse, were outright scams that took advantage of not so wise investors looking to make a buck. Obviously, not all projects fit that description, with many teams still around today working on and delivering their individual visions. Crypto is, after all, still a big experiment of new technology.

Enter DeFi: Serum

DeFi has exploded into the limelight over the last few months, with some tokens appreciating hundreds of percent in price. It appears to be the catalyst that has driven a huge market shift in the crypto world, and for those who’ve been around a number of years, this is a welcome change.
In this piece, I’m going to examine a particular project called Serum.
Serum is the world’s first completely decentralized derivatives exchange with trustless cross-chain trading brought to you by Project Serum.
The Serum Project is aiming to create both a decentralised exchange and a cross-chain swapping mechanism. In this article, I’m going to focus solely on the cross-chain swapping aspect of Serum.
Although the Serum whitepaper is quite short and lacking in detail, it is useful to derive some understanding of how the cross-chain swapping protocol should work. Throughout this review, I will use it to describe how the imagined protocol works.

Overview

Let's assume Alice wants to trade some BTC for ETH and Bob wants to trade some ETH for BTC using Serum. These two users are matched and agree on a price using an on-chain order book on the Solana blockchain (whitepaper provides no practical details on how to do this).
Once these users are matched, Bob must send the ETH he wants to trade to an Ethereum smart contract, plus some amount of ETH ~200 USD worth (see section 4 below) to the smart contract as collateral. Alice will also need to send some collateral to the smart contract. Once this initial setup process is complete Alice then has to send her BTC to Bob’s BTC address and if Bob receives the BTC from Alice he can then release his ETH from the smart contract sending it to Alice’s ETH address. Upon completion of this both Alice and Bob are refunded their ETH collateral.
So what happens if something goes wrong? For example, say Alice never sends BTC to Bob, after some period of time Bob can initiate a dispute. When the dispute begins both Alice and Bob present a portion of the Bitcoin blockchain information to the smart contract (see section 3). The smart contract then decides whether or not Alice did send BTC to Bob. If she hasn’t then the smart contract returns Bob's ETH and collateral to Bob and also takes Alice’s ETH collateral and gives that to Bob. The same occurs in reverse if Alice sends BTC but Bob never approves the transfer of ETH from the smart contract.
This scheme seems pretty simple, there’s no oracles and no centralised parties, however, it has a number of disadvantages.

1. User-Provided Collateral Is Bad for User Experience

Each time a user conducts a swap they must reserve some percentage or fixed amount to cover the collateral for the swap. This collateral amount needs to be present to prevent griefing attacks where users initiate swaps with no intention of ever following through and sending funds to the alternate participant.
However, this creates a poor user experience as both Alice and Bob need to have at least the value of the dispute fee committed to the contract in collateral before they conduct a swap. This is totally foreign from the normal exchange experience in which you only require a single coin and a single transaction to begin trading. For example, if using Serum to trade Bitcoin you would need to hold Bitcoin and ~200$ of Ethereum and also interact with the Ethereum chain before any swap occurs. This adds unnecessary complexity and confusion, especially for newcomers to the crypto space.

2. ETH Must Always Be on One Side of the Swap

Although the Serum method of cross-chain swapping could occur on any blockchain with smart contracts, the Serum whitepaper makes it clear the Serum arbitration contract is going to be deployed on the Ethereum blockchain. This means one party must always be locking the full value of the trade in ETH using an Ethereum smart contract.
This makes it impossible, for example, to do a single step trade between Bitcoin and Monero since the swap would need to be from Bitcoin to ETH first and then from ETH to Monero. This is comparable to other proposed cross-chain swap systems like Thorchain and Blockswap, however since those networks use AMM’s (automated market makers)and decentralized vaults to take custody of funds, the user needs not to interact with the intermediary chain at all.
Instead in Serum, the user wanting to swap Bitcoin to Monero will need to do the following steps:
  1. Send Ethereum collateral to the Serum arbitration contract
  2. Send Bitcoin to the user they are swapping with.
  3. Receive Ethereum
  4. Send Ethereum back to Serum arbitration contract
  5. Receive Monero
  6. Send Ethereum out of Serum arbitration contract
  7. Receive back Ethereum collateral
It might be possible to remove or simplify step 4, depending on how the smart contract is built, however, this means a swap from BTC to Monero would require 2 Ethereum and 1 Bitcoin transaction in the best-case scenario. Compared with the experience of other cross-chain swapping mechanisms, which only require the user to send a single transaction to swap between two assets, this is very poor user experience.

3. Proving Transactions on Arbitrary Chains to a Smart Contract Is Not Trivial

Perhaps the most central part of the Serum cross-chain swapping mechanism is left completely unexplored in the Serum whitepaper with only a brief explanation given.
“[The] Smart Contract is programmed to parse whether a proposed BTC blockchain is valid; it can then check which of Alice and Bob send the longer valid blockchain, and settle in their favor”
This is not a trivial problem, and it is unclear how this actually works from the explanation given in the Serum whitepaper. What actually needs to be presented to the smart contract to prove a Bitcoin transaction? Typically when talking about SPV the smart contract would need the block headers of all previous blocks and a merkle inclusion proof. This is far too heavy to submit in a dispute. Instead, Serum could use NIPoPoW, however, these proofs only work on chains with fixed difficulty and are still probably prohibitively too large (~100KB) to be submitted as a proof to a contract. Other solutions like Flyclient are more versatile, but proof sizes are much larger and have failed to see much real-world adoption.
Without explaining how they actually plan to do this validation of Bitcoin transactions, users are left in the dark about how secure their solution actually is.

4. High Dispute Fees Force Large Collateral on Small Trades

Although disputes should almost never happen because of the incentives and punishments designed into the Serum protocol, the way they are designed has negative impacts on the use of the network.
Although the Serum whitepaper does not say how the dispute mechanism works, they do say that it will cost about ~100 USD in GAS to dispute a swap.
Note: keep in mind that the Serum paper was published in July 2020 when the gas price was about 50 Gwei, as Ethereum use has picked up over the past month we have seen average GAS prices as high as 250 Gwei, with the average price right now about 120 Gwei.
This means that at the height of GAS prices it could have cost a user ~500 USD to dispute a swap.
This means for the network to ensure losing cross-chain swaps aren’t made each user must deploy at least $200 in collateral on each side. It may be possible to lower this to collateral if we assume the attacker is not financially motivated, however, there is a lower bound in which ransom attacks become possible on low-value trades.
Further and perhaps more damagingly, this means in a trade of any size the user needs to have at least 300 USD in ETH laying around. 100 USD in ETH for the required collateral and 200 USD if they need to challenge the transaction.
This further adds to the poor user experience when using Serum for cross-chain swapping.

5. Swaps Are Not Set and Forget

Instead of being able to send a transaction and receive funds on the blockchain you are swapping to, the process is highly interactive. In the case where I am swapping ETH for Bitcoin, the following occurs:
If the Bitcoin transaction is never received then I need to wait for a timeout to occur before I can participate in the dispute process.
And on the Bitcoin side (assuming the seller is ready), the following must take place:
If the Seller never accepts the Bitcoin I sent to him then I need to wait on line for the dispute process.
This presents a strange user experience where the seller or seller’s wallet must be left online during this whole process and be ready to sign a new transaction if they need to dispute transactions or unlock funds from a smart contract.
This is different from the typical exchange or swapping scenario in which, once your funds are sent you can be assured you will receive the amount you expected in your swap back to you, without any of your wallets needing to remain online.

6. The Serum Token Seems to Lack a Use Case

The cross-chain swapping protocol Serum describes in its whitepaper could easily be forked and launched on the Ethereum blockchain without having any need for the Serum token. It seems that the Serum token will be used in some capacity when placing orders on the Solana based blockchain, however, the order book could just as easily be placed off with traditional rate-limiting schemes.
There is some brief mention of future governance abilities for token holders, however, as a common theme in their whitepaper, details are scarce:
Serum is anticipated to include a limited governance model based on the SRM token. While most of the Serum ecosystem will be immutable, some parameters without large security risks (e.g. future fees) may be modified via a governance vote of SRM tokens.

Conclusion

Until satisfactory answers are given to these questions I would be looking at other projects who are attempting to build platforms for cross-chain swaps. As previously mentioned, Thorchain & Blockswap show some promise in design, whilst there are some others competing in this space too, such as Incognito and RenVM. However, this area is still extremely immature so plenty of testing and time is required before we can call any of these projects a success.
If you’ve got any feedback or thoughts about Serum, cross-chain swapping or DeFi in general, please don’t be shy in leaving a comment.
submitted by Loooong_Loooong_Man to CryptoCurrency [link] [comments]

What is really happening in the bitcoin mining process?

What is really happening in the bitcoin mining process?
April 30, 2020 | There’s more than just the sound of thousands of vacuums
It is very easy to just silo the arcane bitcoin mining process as just a bunch of machines computing mathematical algorithms. Although for the most part this is true, and the veracity of this is not far off from the real truth, but what we see on the surface is not identical to what we see below the surface. Understanding bitcoin mining goes beyond the USB enabled ASIC miners we are accustomed to see on every thumbnail article we come across related to this industry.

It’s easy to understand why newbies halt their understanding of bitcoin mining to just state-of-the-art supercomputers with cool flickering neon green lights.
The following below is taken from the masterpiece of a novel, “Mastering Bitcoin”, by the great Andreas Antonopolous. As elegant as it sounds, its best to restate Andreas’ explanation of emergent consensus.
“Satoshi Nakamoto’s main invention is the decentralized mechanism for emergent consensus. Emergent, because consensus is not achieved explicitly — there is no election or fixed moment when consensus occurs. Instead, consensus is an emergent artifact of the asynchronous interaction of thousands of independent nodes, all following simple rules. All the properties of bitcoin, including currency, transactions, payments, and the security model that does not depend on central authority or trust, derive from this invention.
Bitcoin’s decentralized consensus emerges from the interplay of four processes that occur independently on nodes across the network:
  • Independent verification of each transaction, by every full node, based on a comprehensive list of criteria
  • Independent aggregation of those transactions into new blocks by mining nodes, coupled with demonstrated computation through a proof-of-work algorithm
  • Independent verification of the new blocks by every node and assembly into a chain
  • Independent selection, by every node, of the chain with the most cumulative computation demonstrated through proof of work”
The following is a scenario taken from the book as well which excellently demonstrates what is going on with a mining node and its corresponding connected miner machine:
“A mining node is listening for transactions, trying to mine a new block and also listening for blocks discovered by other nodes. The arrival of this block signifies the end of the competition for block 277,315 and the beginning of the competition to create block 277,316. During the previous 10 minutes, while Jing’s node was searching for a solution to block 277,315, it was also collecting transactions in preparation for the next block. By now it has collected a few hundred transactions in the memory pool. Upon receiving block 277,315 and validating it, Jing’s node will also check all the transactions in the memory pool and remove any that were included in block 277,315. Whatever transactions remain in the memory pool are unconfirmed and are waiting to be recorded in a new block. Jing’s node immediately constructs a new empty block, a candidate for block 277,316. This block is called a candidate block because it is not yet a valid block, as it does not contain a valid proof of work. The block becomes valid only if the miner succeeds in finding a solution to the proof-of-work algorithm.
These specialized machines are connected to his mining node over USB. Next, the mining node running on Jing’s desktop transmits the block header to his mining hardware, which starts testing trillions of nonces per second.”
That is essentially the process of what a miner machine and a mining node is going through each every second it is hooked up to the network. Of course this is just a high level overview with a bland taste but one could go more in depth by reading the book mentioned.
Source:
1.Mastering Bitcoin: Unlocking Digital Cryptocurrencies 1st Edition, by Andreas M. Antonopoulos, O’Reilly Media; 1 edition (December 20, 2014)
submitted by 1TMine to u/1TMine [link] [comments]

Bitcoin Resources in Spanish

Hello I am trying to get a coworker of mine into Bitcoin, I only nabahed to explain the bare bones of it but would like deeper info. he seems interested in it but since his main language is Spanish is there any resources like articles, YouTube, books, etc., about Bitcoin and all the ins and outs of how it works, the Block Chain information, and what is the lightning network and how it works. The information about exchanges is also good because my explanation arent great when i was giving info and resources would be cool. Thank you guys.
submitted by DestinedEsper to BitcoinBeginners [link] [comments]

My top 5 (and more) arguments against the mining tax as implemented in ABC 0.21.0

These are mine, but I'd like to hear yours in the comments!
  1. Corrupting influence. Mixing monetary policy (money supply regulation, in Bitcoin: coin creation) and fiscal policy (roughly: government spending and taxing) is what central banks already do, and we know the results. Bitcoin was not designed to deliver such a mix - the newly created coin was, up to now, fully owned by the miner creating the block, and matures after a certain time when it can be spent. Miners can voluntary spend their coinbase outputs to other parties already. In this way fiscal decisions are decentralized as much possible - meaning every miner / pool gets to decide how to spend 100% of their mining block reward (or share thereof). Do you already see how Bitcoin's design removes all possible financial intermediaries - including any trusted "government" or "fund" that decides how to spend other peoples' money? If so, you already get my first point. Peter Rizun has mentioned the legal concerns around directing colluding miner funds to certain entities with expectation of results. IANAL, but I think the argument that instituting such a change on protocol level could bring BCH into conflict with security law (Howey Test) should be seriously examined.
  2. Due to how information is distributed, a centrally planned economy cannot match the efficiency of the open market. A free market is all that is needed to fund things. Miners and anyone else can already fund any kind of development (or other activities) through the existing protocol. Furthermore, we know there are successful methods of funding public goods in voluntary ways through Assurance Contracts. These have not been deployed on Bitcoin Cash before (early crowdfunding systems didn't implement them properly), but are basically ready to go now (Flipstarter) and could offer BCH an improvement even over other successful systems like Monero's Community Crowdfunding System (CCS) due to the fact that we can do this non-custodially via Bitcoin Cash scripts. Going for a miner tax based "dev fund" with nebulous administration and all the accompanying hazards seems a poor choice before we tried the voluntary route which preserves the original economic freedom and incentives of Bitcoin Cash.
  3. Increased centralization of mining and development. Going with the plan would work counter to a decentralized protocol client environment, and centralize even more power with the dominant client (ABC). The donation address whitelist is hardcoded into the client. Miners/pools who don't obey the new rules of contributing 5% of block reward to active whitelisted addresses have their blocks orphaned, lowering the chain hashrate (security) and driving away small miners who might not be able to afford the margin. This centralizes mining on BCH beyond what's necessary. Again, a free market will deliver better security and service!
  4. Sold with a veneer of false pretenses. We are told that other (non-BCH) SHA256 miners will effectively pay the cost, but this argument has been effectively debunked. The cost is paid for all BCH holders, as it comes out of the agreed upon money supply inflation. It comes at the cost of lowered BCH chain hashrate = security, with the concomitant increased risk of other miners executing attacks on BCH. Yet, holders don't get to vote right now, except by selling their BCH or converting it into hashpower. Did you know financial markets can offer instruments to let holders express their opinion about possible futures (whether they'd prefer one outcome or another) with slight or no punishment in the case of no split - i.e. actually could facilitate a no-split outcome that many BCH users & holders recognize as preferable? Another pretense is that the plan, if successful, would terminate after a limited time. This is not what regularly happens in taxpayer-funded government programs, and it is paradoxical to assume that a measure to support ongoing maintenance and development would, if deemed successful in a trial run, be expected to be terminated. Especially if the people receiving the funds are literally the ones deciding and writing the rules. In governments we at least came up with separation of powers (legislative, judicial, executive). Why should be mix up powers again? Absolute power corrupts absolutely. Serious developers also recognize that the dollar amounts we are talking about in the proposed plan are too low to expect completion within the previously announced limited timeframes. Giving a good hint that the limited timeframe was a nothing but a public pacifier when planners already expect it to continue.
  5. The proposal is poorly conceived in terms of safety against malicious activation. Only 66% of hashrate need to vote for it over a two week period. Previously, BCH miners objected to any form of hashrate voting on BCH with the argument that it is still a very-low hashrate minority fork. That has not changed materially, but suddenly we are supposed to accept that hashrate voting on our minority coin is safe. Can't have it both ways. As an additional point, there is no 6 month sunset clause built into the implementation, and it seems removed from the plan agreed between ABC and miners (as per recent ABC website post). This completely reneges on the "update" previously presented to the community in that regard, re-affirming that there is no serious commitment to ending this after a limited time.
I probably squeezed in too many explanations.
Originally my aim was to get a short summary. I should try to sum it up better, but I know there are many people who could do a much better job at that. Please speak up, correct me where you feel I'm wrong, and add points that you think are missing!
P.S. I fully realize that the ones pushing this plan are not likely to be swayed by any of these arguments.
I am presenting mine here in hopes to encourage further discussion, and I hope you will do the same, so everyone is armed with knowledge, going into what looks like it could be an escalating dispute within our community.
Perhaps though, there is a minute chance that backers of the plan could see the danger in the split that they are creating. I still have hope, but I'm also prepared to act.
submitted by ftrader to btc [link] [comments]

A breakdown of the aelf blockchain whitepaper — Part 2

A breakdown of the aelf blockchain whitepaper — Part 2

https://preview.redd.it/p9cf7c4cpri51.png?width=512&format=png&auto=webp&s=006d466a2d0ad4d4afbbffe340eb2ad44631ad27

Breaking down the aelf side-chain

Cloud computing, parallel processing, and AEDPoS have greatly improved the execution performance of any kind of smart contract, but when they are applied to enterprise-level scenarios, new problems crop up. To begin with, in software design, it is a rather bad idea to program all the methods in the same class. We always write a series of classes to inherit a base class, in order to decouple the functionalities and make the class extensible whenever needed. The same also applies to blockchain design. Second, since all the data and transactions are accessible to anyone through a blockchain explorer, if we put the smart contract and data of different enterprises or government sectors on a single blockchain, then everyone can see them, which means there will be no data privacy. Although there are encryption techniques which can mask data, such as zero knowledge proof, it is always better to put the data of different enterprises on different blockchains.
Based on these considerations, long before other projects even realized it, aelf proposed that side-chain technology should be applied to this scenario. Unfortunately, for someone who is new to blockchain, it is almost impossible to understand how side-chain works. Side-chain is not what it literally means, it is not subordinate to the main chain. On the contrary, a side chain is a blockchain distributed system with the same functions and nodes as a main chain (say, the aelf blockchain). As mentioned above, we can put the data of different enterprises on different blockchains. This means we can build many blockchains, and work magic (of course not magic in its literal sense) to make these chains connect to the aelf main chain (in fact, we can call any of these blockchains a main chain and the rest side chains). Currently, the most popular method of connecting any two blockchains, which we also call cross-chain, is using a middle-man. When we want to use bitcoin to play a decentralized game on Ethereum, we need to send a transaction with some amount of bitcoin to a locking bitcoin address, then the middle-man will exchange the locked BTC for ETH at a certain exchange rate and allocate to you the equivalent amount of ETH on Ethereum, which you can use for playing games.
But in aelf, we use a metadata indexing method, which is more straightforward. Unlike other projects who built on the blockchains of those already successful projects (such as Ethereum or the HyperLedger fabric framework for consortium blockchains), the aelf team has writen all the code and build the infrastructure from scratch. From the beginning, the aelf team has defined how the data structure of a blockchain, a block, a transaction etc. should look like in C#. In an aelf blockchain data structure, there is an attribute called blockchain ID, which is a unique hash; and in block data structure, there are several attributes called blockchain ID , Merkle tree root and related side chain block list. There is also one more important thing: all of aelf’s data structures are serialized and stored in Redis (a popular key-value pair database system), so is the side chain information. As a result, as the aelf main chain is growing with block production by BPs, other side chains can send transactions to cross-chain contracts, which then execute the related code to connect to the main chain’s network port and request the main chain to index the side chain block and pay the indexing fee.
The core issue here is how to index a side chain: when a main chain (the block data structure on the main chain, or the data records with main chain ID in Redis), receives a request from a side chain, it adds the side chain’s block head data structure to the related side chain block list, which means theoretically we have indexed or related a side chain. We have mentioned that there is also a blockchain ID in each block, this attribute allows a main chain to index blocks from different side chains. When a user on a main chain wants to access data on a side chain or vise versa, they just need to find the target block on the main chain and its related side chain block list, and then find the target block on the side chain via key indexing.
As we will explain later, blockchains for different application scenarios generate blocks at different speeds. Under such circumstances, a chain with slower speed might index many blocks from a chain that produces blocks faster. This method can be applied to scenarios such as forking.
In practice, we can build any number of blockchains, and relate it via indexing to the aelf main chain, with a specific category of smart contracts running on each of them. For example, we can allow only banking-related smart contracts deployed on a specific blockchain, and e-commerce smart contracts on another. Our whitepaper summarizes it best:
One chain, one contract.
Moreover, the indexing method can make many blockchains into a hierarchical tree structure, the root being the so-called main chain. That’s because a related blockchain can then again index another blockchain as its side chain, and the process can keep going on. Logically, this is in perfect accordance with hierarchical taxonomy, for example, the financial sector has many subcategories, such as banking, lending, investment and insurance, and under investment banking, there are venture capital, investment bank etc… Each subcategory is supported by an indexed blockchain.
So how do these blockchains collaborate in a distributed system? First we need to be know that any node in a distributed system is just a software instance running on your computer, or a process. In TCP/IP, a node is allocated a port number, so we can run any number of this type of instances on a computer. However, each instance has its own port number: we can run several blockchain nodes, one IPFS node, one bit-torrent node and etc. simultaneously. In aelf, you should first start a main chain instance, and then you can build and run a side chain instance. Transactions broadcast on the side chain are collected by the BP nodes (block production nodes) on the main chain. When smart contracts deployed on the side chain is triggered, the BP and full nodes on the main chain will run them.

Aelf — a blockchain based operating system

To perfect the design of our software system, aelf made the system extensible, flexible and pluggable. Just as there are thousands of Linux OS with only one Linux kernel. As Ethereum Founder Vitalik Buterin has explained, Ethereum can be seen as a world computer because there are lots of smart contracts running on it, and the contract execution results are consistent in all the distributed systems around the world. This idea is also embedded in aelf’s system and we call it a “blockchain infrastructure operating system”, or a distributed operating system.
Just like any OS, aelf has a kernel and a shell. In fact, aelf’s kernel is not something like a Linux kernel, it is just an analogy. There is a special concept in aelf’s kernel called the minimum viable blockchain system, which defines the most fundamental aspect of a blockchain. If a developer wants to create a new blockchain system or a new blockchain project, he does’t have to start from scratch, instead, he can directly extend and customize using the aelf blockchain open-source code. The technologies described above are all included in the minimum viable blockchain system. With these, anyone can customize:
  • Block property: block data structure, block packaging speed, transaction data structure, etc.
  • Consensus type: AEDPoS is used by default, but you can also use incentive consensus, like PoW and PoS. And you can also use the consensus of traditional distributed systems, like PoS and Practical Byzantine Fault Tolerance, or PBFT. In fact, the f evil nodes of 3f+1 nodes are the upper limit for any distributed system to reach a consensus, which is called the Byzantine Fault Tolerance, or BFT. In order to do this, there is a specific algorithm, but in 1999, a much more efficient algorithm to reach this consensus came along, that is the PBFT. In scenarios like private blockchain or consortium blockchain where there is no need for a incentive model, PBFT will be a good option.
  • Smart contract collection: In aelf, there are many predefined smart contracts that can be used directly by other contracts, such as token contract, cross-chain contract (also called CCTP, or cross chain transfer protocol), consensus contract, organization voting contracts, etc. Of course, you can also create your own contract with a brand new implementation logic.
  • Others.

Summary

So this is our breakdown of the aelf blockchain whitepaper. In previous articles, we first introduced two basic concepts which are often misinterpreted by other articles. After helping you get these two concepts straight, we then introduced aelf’s vast arsenal of powerful technology. If these articles helped you understand the aelf blockchain better, then I have reached my goal. But I must advise you to read the whitepaper for a more detailed explanation. With all this knowledge at your disposal, I believe you will be much more comfortable developing DApps on aelf.
Check Part 1 here: https://medium.com/aelfblockchain/a-breakdown-of-the-aelf-blockchain-whitepaper-part-1-a63fc2e3e2e7
submitted by Floris-Jan to aelfofficial [link] [comments]

A tech noob’s questions answered observations. (Just bought one BTC and dumped it because there are things I don’t get)

Hey all!
I bought a BTC (CORE) and almost immediately got rid of it (at the smallest of profits). I dumped it because I had the following issues with the Bitcoin community, and I’m hoping my questions will be resolved. I’m aware this is the subreddit for BCH, which is case-and-point for some of the issues I have. I’d love feedback or explanations.
My issues with the BTC community:
  1. HODL culture.
I’m no great technician, but as a layman my understanding of Bitcoin’s value is that it lies in its utility. I.e. if Bitcoin has a utilitarian function its value may increase versus fiat, but regardless, that isn’t the point of Bitcoin. It isn’t to make an individual wealthy ala currency trading (although it’s amazing if it does), it’s to create a fully functional currency. Advocating for HODLing, being derisive towards subreddit members who have “weak hands”, these are signs of people who have missed the forest for the trees, intellectual supremacists who set aside the idea the notion of assigning any sort of functionality to their knowledge and instead worship it for its own sake. To me this seems a path to nowhere.
  1. The air of superiority intertwined with paranoia as a whole and refusal to help those who are newcomers while accusing them of being “altcoin shills”.
If the purpose of this technology is to unite the common man against the system, doesn’t it follow that the users of this technology should seek to make themselves and their tech more accessible to the layman? Instead, it seems to me that the Bitcoiners exhibit a strange blend of paranoia and narcissism. They assume everyone who asks a question is both, beneath them and a well-versed opponent assuming subterfuge. Therefore they don’t engage in conversation which might otherwise be enlightening for the sake of not giving the trolls food. I don’t get this. Should the merits of their arguments not be strong enough that they welcome intellectual curiosity, even if it’s at the hands of one who supports a different subset of the same technology they so enthusiastically propagate?
  1. The apparent lack of interest in intellectual honesty where the improvement of the technology itself is concerned.
Again, I might be wrong here, but it seems that the community as a whole obeys top-down directives when it comes to updating the chain. Now I’m no techie and I don’t understand lightning network (which may very well be better than increased block sizes) but doesn’t this negate the ‘decentralization mandate’?(I use the term mandate tongue-in-cheek). If we are deferring to higher ups, why not just rely on Banks and Governments and be done with it?
Problems I have with BCH AS WELL AS BTC
  1. Practicality
It seems to me that the simplest, most practical cryptocrypto will be the first one to gain mass approval and appeal. It also seems to me that no single coin has made any sort of great strides towards that practicality. Sure, if you’re a tech enthusiast some of the larger cryptos have become much easier to use, but not if you’re a layman. How does the community view this way of thinking?
  1. Crypto-education
Even if one cryptocurrency is much easier to use, I don’t know about it. This is largely because there is a lack of education among the populace, almost as much as there is disinformation about the how and why of cryptos existence. How does a crypto community view trying to go about solving this problem, especially being as decentralized as it is?
There’s more that I’m curious about, but this is plenty off the top of my head. I’d love to hear your thoughts on this.
submitted by the_wreckes to btc [link] [comments]

List of Today's and Tomorrow's Upcoming Events

I will be bringing you upcoming events/announcements every day. If you want improvements to this post, please mention houseme in the comments. We will make improvements based on your feedback.
 
https://kryptocal.com | /kryptocal | Android | iOS | Telegram Interactive Bot (add cryptocalapp_bot) | Telegram Channel @kryptocal
 

ADD AN EVENT

If you like an event to be added, click Submit Event, and we will do the rest.
 

NEXT DAY UPCOMING EVENTS

 
General
Cardano(ADA) Shelley Hardfork July 29, 2020
Enigma(ENG) AMA July 29, 2020
Enjin Coin(ENJ) AMA w/AlterVerse CEO July 29, 2020
BiblePay(BBP) Graviex Delisting July 29, 2020
Bitcoin Diamond(BCD) Halving July 29, 2020
Huobi Token(HT) AMA w/HuobiFutures July 29, 2020
BitTube(TUBE) Hardfork July 29, 2020
STASIS EURS(EURS) Live AMA July 29, 2020
Kava(KAVA) Crypto Pay Day July 29, 2020
PhoenixDAO(PHNX) PhoenixDAO AMA GemHunters July 29, 2020
NOIA Network(NOIA) Telegram AMA July 29, 2020
BitShares(BTS) Mainnet Upgrade July 30, 2020
ChainLink(LINK) ETH in the Enterprise July 30, 2020
ZenCash(ZEN) Weekly Insider #51 July 30, 2020
Stox(STX) CryptoZoom Arabia AMA July 30, 2020
BestChain(BEST) BEST Token Burn July 30, 2020
Elastos(ELA) 80% Token Burn July 30, 2020
Transcodium(TNS) TNS Burn Phase 5 July 30, 2020
BlockTrade(BTT) AMA w/BTT CEO July 30, 2020
Elrond(ERD) Mainnet Launch July 30, 2020
Aergo(AERGO) MTO Round 4 July 30, 2020
Harmony(ONE) June Newsletter July 30, 2020
CCUniverse(UVU) Explanation Video July 30, 2020
DEEX(DEEX) Stable Smart Coin on Deex July 30, 2020
ShareToken(SHR) AMA July 30, 2020
Livepeer(LPT) Community Call July 30, 2020
BOLT(BOLT) BOLT Vault #31 July 30, 2020
RESQ Chain(RESQ) Crex24 Delisting July 30, 2020
 
Exchanges
Skycoin(SKY) XBTS.io SCH Listing July 29, 2020
ZelaaPayAE(ZPAE) Probit Listing July 29, 2020
ADAMANT Messenger(ADM) ATOMARS Listing July 29, 2020
UCA Coin(UCA) LBank Listing July 29, 2020
BABB(BAX) Exchange Listing July 30, 2020
Energi(NRG) Indodax Listing July 30, 2020
NEXT.coin(NEXT) Exchange Listing July 30, 2020
Crypto.com Coin(CRO) Bittrex EURO Pair Listing July 30, 2020
 
Meetups
Stox(STX) Blockstack Meetup July 29, 2020
 
Partnerships
StormX(STMX) New Partner Announcement July 29, 2020
 
Fork/Hard Forks
Zilliqa(ZIL) Town Hall July 30, 2020
 
 
submitted by cryptocalbot to CryptoMarkets [link] [comments]

List of Today's and Tomorrow's Upcoming Events

I will be bringing you upcoming events/announcements every day. If you want improvements to this post, please mention houseme in the comments. We will make improvements based on your feedback.
 
https://kryptocal.com | /kryptocal | Android | iOS | Telegram Interactive Bot (add cryptocalapp_bot) | Telegram Channel @kryptocal
 

ADD AN EVENT

If you like an event to be added, click Submit Event, and we will do the rest.
 

NEXT DAY UPCOMING EVENTS

 
General
Cardano(ADA) Shelley Hardfork July 29, 2020
Enigma(ENG) AMA July 29, 2020
Enjin Coin(ENJ) AMA w/AlterVerse CEO July 29, 2020
BiblePay(BBP) Graviex Delisting July 29, 2020
Bitcoin Diamond(BCD) Halving July 29, 2020
Huobi Token(HT) AMA w/HuobiFutures July 29, 2020
BitTube(TUBE) Hardfork July 29, 2020
STASIS EURS(EURS) Live AMA July 29, 2020
Kava(KAVA) Crypto Pay Day July 29, 2020
PhoenixDAO(PHNX) PhoenixDAO AMA GemHunters July 29, 2020
NOIA Network(NOIA) Telegram AMA July 29, 2020
BitShares(BTS) Mainnet Upgrade July 30, 2020
ChainLink(LINK) ETH in the Enterprise July 30, 2020
ZenCash(ZEN) Weekly Insider #51 July 30, 2020
Stox(STX) CryptoZoom Arabia AMA July 30, 2020
BestChain(BEST) BEST Token Burn July 30, 2020
Elastos(ELA) 80% Token Burn July 30, 2020
Transcodium(TNS) TNS Burn Phase 5 July 30, 2020
BlockTrade(BTT) AMA w/BTT CEO July 30, 2020
Elrond(ERD) Mainnet Launch July 30, 2020
Aergo(AERGO) MTO Round 4 July 30, 2020
Harmony(ONE) June Newsletter July 30, 2020
CCUniverse(UVU) Explanation Video July 30, 2020
DEEX(DEEX) Stable Smart Coin on Deex July 30, 2020
ShareToken(SHR) AMA July 30, 2020
Livepeer(LPT) Community Call July 30, 2020
BOLT(BOLT) BOLT Vault #31 July 30, 2020
RESQ Chain(RESQ) Crex24 Delisting July 30, 2020
 
Exchanges
Skycoin(SKY) XBTS.io SCH Listing July 29, 2020
ZelaaPayAE(ZPAE) Probit Listing July 29, 2020
ADAMANT Messenger(ADM) ATOMARS Listing July 29, 2020
UCA Coin(UCA) LBank Listing July 29, 2020
BABB(BAX) Exchange Listing July 30, 2020
Energi(NRG) Indodax Listing July 30, 2020
NEXT.coin(NEXT) Exchange Listing July 30, 2020
Crypto.com Coin(CRO) Bittrex EURO Pair Listing July 30, 2020
 
Meetups
Stox(STX) Blockstack Meetup July 29, 2020
 
Partnerships
StormX(STMX) New Partner Announcement July 29, 2020
 
Fork/Hard Forks
Zilliqa(ZIL) Town Hall July 30, 2020
 
 
submitted by cryptocalbot to kryptocal [link] [comments]

A Glance at the Heart: Proof-of-Authority Technology in the UMI Network

A Glance at the Heart: Proof-of-Authority Technology in the UMI Network

https://preview.redd.it/vhvj6v093df51.jpg?width=1024&format=pjpg&auto=webp&s=00c0c223d9758edec8ed49a8cb9024f96d3ee343
Greetings from the UMI Team! Our Whitepaper describes in detail the key pros and cons of the two mechanisms which the great majority of other cryptocurrencies are based on:
Proof-of-Work (PoW) — mining technology. Used in Bitcoin, Ethereum, Litecoin, Monero, etc.
Proof-of-Stake (PoS) and its derivatives — forging technology. Used in Nxt, PeerCoin, NEO, PRIZM, etc.
As a result of a careful analysis of PoW and PoS, which are designed to fight against centralization, there came a conclusion that they both fail to perform their main mission and, in the long run, they lead to the network centralization and poor performance. For this reason, we took a different approach. We use Proof-of-Authority (PoA) algorithm coupled with master nodes, which can ensure the UMI network with decentralization and maximum speed.
The Whitepaper allows you to understand the obvious things. This article will give you a clear and detailed explanation of the technology implemented in the UMI network. Let's glance at the heart of the network right now.
Proof-of-Authority: How and Why It Emerged
It's been over a decade since the first transaction in the Bitcoin network. Over this time, the blockchain technology has undergone some qualitative changes. It's down to the fact that the cryptocurrency world seeing the emerging Proof-of-Work defects in the Bitcoin network year after year has actively searched for ways to eliminate them.
PoW decentralization and reliability has an underside of low capacity and scalability problem that prevents the network from rectifying this shortcoming. Moreover, with the growing popularity of Bitcoin, greed of miners who benefit from high fees resulting from the low network throughput has become a serious problem. Miners have also started to create pools making the network more and more centralized. The “human factor” that purposefully slowed down the network and undermined its security could never be eliminated. All this essentially limits the potential for using PoW-based cryptocurrencies on a bigger scale.
Since PoW upgrade ideas came to nothing, crypto community activists have suggested cardinally new solutions and started to develop other protocols. This is how the Proof-of-Stake technology emerged. However, it proved to be excellent in theory rather than in practice. Overall, PoS-based cryptocurrencies do demonstrate a higher capacity, but the difference is not as striking. Moreover, PoS could not fully solve the scalability issue.
In the hope that it could cope with the disaster plaguing all cryptocurrencies, the community came up with brand new algorithms based on alternative operating principles. One of them is the Proof-of-Authority technology. It was meant to be an effective alternative with a high capacity and a solution to the scalability problem. The idea of using PoA in cryptocurrencies was offered by Gavin Wood — a high-profile blockchain programmer and Ethereum co-founder.
Proof-of-Authority Major Features
PoA's major difference from PoW and PoS lies in the elimination of miner or forger races. Network users do not fight for the right to be the first to create a block and receive an award, as it happens with cryptocurrencies based on other technologies. In this case blockchain's operating principle is substantially different — Proof-of-Authority uses the “reputation system” and only allows trusted nodes to create blocks.
It solves the scalability problem allowing to considerably increase capacity and handle transactions almost instantly without wasting time on unnecessary calculations made by miners and forgers. Moreover, trusted nodes must meet the strict capacity requirements. This is one the main reasons why we have selected PoA since this is the only technology allowing to fully use super-fast nodes.
Due to these features, the Proof-of-Authority algorithm is seen as one of the most effective and promising options for bringing blockchain to various business sectors. For instance, its model perfectly fits the logistics and supply chain management sectors. As an outstanding example, PoA is effectively used by the Microsoft Azure cloud platform to offer various tools for bringing blockchain solutions to businesses.
How the UMI Network Gets Rid of the Defects and Incorporates the Benefits of Proof-of-Authority Method
Any system has both drawbacks and advantages — so does PoA. According to the original PoA model, each trusted node can create a block, while it is technically impossible for ordinary users to interfere with the system operation. This makes PoA-based cryptocurrencies a lot more centralized than those based on PoW or PoS. This has always been the main reason for criticizing the PoA technology.
We understood that only a completely decentralized product could translate our vision of a "hard-to-hit", secure and transparent monetary instrument into reality. Therefore, we started with upgrading its basic operating principle in order to create a product that will incorporate all the best features while eliminating the defects. What we’ve got is a decentralized PoA method. We will try to explain at the elementary level:
- We've divided the nodes in the UMI network into two types: master nodes and validator nodes.
- Only master nodes have the right to create blocks and confirm transactions. Among master node holders there's the UMI team and their trusted partners from across the world. Moreover, we deliberately keep some of our partners — those who hold master nodes — in secret in order to secure ourselves against potential negative influence, manipulation, and threats from third parties. This way we ensure maximum coherent and reliable system operation.
- However, since the core idea behind a decentralized cryptocurrency rules out any kind of trust, the blockchain is secured to prevent master nodes from harming the network in the event of sabotage or collusion. It might happen to Bitcoin or other PoW- or PoS-based cryptocurrencies if, for example, several large mining pools unite and perform a 51% attack. But it can’t happen to UMI. First, the worst that bad faith master node holders can do is to negligibly slow down the network. But the UMI network will automatically respond to it by banning such nodes. Thus, master nodes will prevent any partner from doing intentional harm to the network. Moreover, it will not be able to do this, even if most other partners support it. Nothing — not even quantum computers — will help hackers. Read our post "UMI Blockchain Six-Level Security" for more details.
- A validator node can be launched by any participant. Validator nodes maintain the network by verifying the correctness of blocks and excluding the possibility of fakes. In doing so they increase the overall network security and help master nodes carry out their functions. More importantly, those who hold validator nodes control those who hold master nodes and confirm that the latter don't violate anything and comply with the rules. You can find more details about validator nodes in the article we mentioned above.
- Finally, the network allows all interested users to launch light nodes (SPV), which enables viewing and sending transactions without having to download the blockchain and maintain the network. With light nodes, any network user can make sure if the system is operating properly and doesn't have to download the blockchain to do this.
- In addition, we are developing the ability to protect the network in case 100% of the master nodes (10,000 master nodes in total) are "disabled" for some reason. Even this is virtually impossible, we've thought ahead and in the worst-case scenario, the system will automatically move to PoS. By doing so, it will be able to continue processing transactions. We're going to tell you about this in our next publications.
Thus, the UMI network uses an upgraded version of this technology which possesses all its advantages with drawbacks eliminated. This model is truly decentralized and maximum secured.
Another major drawback of PoA-based cryptos is no possibility to grant incentives to users. PoA doesn't imply forging or mining which allow users to earn cryptocurrency while generating new coins. No reward for maintaining the network is the main reason why the crypto community is not interested in PoA. This is, of course, unfair. With this in mind, the UMI team has found the best solution — the unique staking smart-contract. It allows you to increase the number of your coins up to 40% per month even with no mining or forging meaning the human factor cannot have a negative impact on the decentralization and network performance.
New-Generation Proof-of-Authority
The UMI network uses an upgraded version of PoA technology which possesses all its advantages with drawbacks virtually eliminated. This makes UMI a decentralized, easily scalable, and yet the most secure, productive, profitable and fair cryptocurrency, working for the sake of all people.
The widespread use of UMI can change most aspects of society in different areas, including production, commerce, logistics, and all financial arrangements. We are just beginning this journey and thrilled to have you with us. Let's change the world together!
Best regards, UMI Team!
submitted by UMITop to u/UMITop [link] [comments]

Bitcoin Unlimited Response to the Claim that our organisation supports BSV

Bitcoin Unlimited Response to the Claim that our organisation supports BSV

https://preview.redd.it/3ln9aepxr5g41.png?width=1024&format=png&auto=webp&s=01759a0c70f4ab54316c12d61b907d2e17c63368
We recently ran a survey of the Bitcoin Cash community because your opinions are extremely important to us. Thank you to all of you who gave us feedback, it was much appreciated. If any of you would still like to complete the survey it can be found HERE. We gained lots of useful insights from this feedback and we intend to use this to offer even more value to the BCH ecosystem.

Some Issues We Need To Clarify

The survey did also bring to light a number of issues which require some clarity. One key issue that a number of respondents mentioned was that they felt BU was in support of BSV or BTC. We felt that this was something we needed to correct ASAP as this could not be further from the truth. From the moment the BCH was created (and even long before), BU has been working tirelessly in support of BCH through many different initiatives that were voted on by the BU membership. BU continues to have 100% of its resources devoted to supporting the Bitcoin Cash ecosystem.
Bitcoin Unlimited operates through a voting process whereby members of the organisation propose BUIPs (BU improvement proposals) which are then voted on by the membership. Proposals that receive the required number of votes in favour are considered to be successful and the organisation will support them. In this way Bitcoin Unlimited makes itself both guided by and accountable to its membership.
It is true that some (a minority) of BU members are supporters of BitcoinSV, and this can cause some conflict. This is unfortunately one of the many negative artefacts from a split happening in a decentralised currency. Even so, the Bitcoin Unlimited organisation has remained not only focused and functional, but also strongly in support of Bitcoin Cash. In fact, the BU membership and the organisation’s governance model has shown time and time again that BU is fully in support of BCH - a peer to peer electronic cash system. The voting results from the relevant BUIPs support this fact. Below you will find the voting results for all BUIP related to the BCH/BSV issue, and you will see that at every opportunity BU as an organisation has voted in support of BCH.

BUIP No. BUIP TITLE RESULT SUMMARY
BUIP098 BU Strategy for Nov 2018 upgrade FOR Tried to stop the ecosystem from splitting.
BUIP101 Default max blocksize cap (hard limit) 10 TB AGAINST Blocked a BSV supporting major change.
BUIP107 Sell the BCH portion of BU funds for BSV AGAINST Voted down holding any BSV.
BUIP113 Support BSV with Official Implementation AGAINST Denounced BSV in support of BCH.
BUIP114 Drop Support of BSV HF Config Params in BUCash FOR Denounced BSV in support of BCH.
BUIP115 Drop support for BTC FOR Denounced BTC (formally).
BUIP127 Partially re-weight 50% BTC to BCH AGAINST Voted to not buy more BCH using BTC.

Where This Confusion Has Come From

We speculate that some of the confusion also comes from two sources. First, the fact that BUIP098 required BU to implement some features proposed by nChain that became part of BSV. BU implemented these features (after a BUIP was approved) for the miners to vote on them in the hopes this would avoid a split. Post-fork no BSV related commits were made and these features were removed. Additionally, many of these features are on the BCH roadmap (scalability, etc), so supporting implementation and compromise actually would further BCH’s goals.
Second, BU officers posted statements (in their own capacity, not as official BU statements) arguing to delay or stop the proposed CTOR feature. Dispute over a specific feature cannot and should not be construed as support for another blockchain.
It was important to also include BUIP127 “Partially re-weight 50% BTC to BCH” in this list (which was voted down) as this has been cause for some to claim BU does not support BCH, even in light of the significant evidence to the contrary. This specific issue requires a much more detailed explanation and therefore deserves it’s own article, which is to be published shortly.
We hope this has hopefully cleared up some of the confusion within the community, and shows BU’s continued commitment to Bitcoin Cash.
----------------------------- If you are interested in becoming a member of BU and help guide the organisation then get in touch HERE.
submitted by BU-BCH to btc [link] [comments]

The real upgrade happened on August 1st, 2017

The difference between a chain with Segwit/1MB and Segwit/2MB is negligible anyway. Neither 1MB nor 2MB is anywhere near enough to scale on chain competitively.
On Chain Capacity of the three likely forks:
  1. Segwit1x - ~ 3 tx/s with 0% segwit usage, ~5 tx/s with 100% segwit usage.
  2. Segwit2x - ~ 6 tx/s with 0% segwit usage, ~10 tx/s with 100% segwit usage.
  3. Bitcoin Cash (Original Bitcoin protocol), ~100 tx/s on chain with 32MB blocks before another hard fork is required for scale.*
*Important to note that the 8MB limit on the cash fork is not a hard limit, meaning miners can scale above 8MB without needing another protocol upgrade (hard fork.) The original Bitcoin protocol that Satoshi built scaled all the way to 32MB, before the 1MB spam protection limit was added.
Bitcoin Cash is the original protocol with the limit removed so it scales all the way to 32MB before another hard fork (protocol upgrade) is needed.
This means the Cash fork is capable of delivering 100tx/s on chain, today.
That is ten times what the Segwit2x fork can do under optimal conditions.
submitted by poorbrokebastard to btc [link] [comments]

Questions Regarding BTC Mining

I have been wondering about some of the details related to bitcoin mining bit couldn't find an answer, I would bet the answer can be found was I capable of looking up the mining algorithms but I'm not that savvy (not yet at least) so here it goes.
I understand that during mining, the miners take the hash calculated from a given block then appends a nonce to it and calculate SHA256 for the whole expression, if the hash value is larger than the limit set by mining difficulty, the miner must attempt again the SHA256 calculation again by appending a different nonce and repeat until a hash smaller than the limit is found.
What I wanted to ask is the following:
1) Is my understanding above correct? If not then please disregard the below questions since they would be garbage most likely (correcting the fault lines in my understanding would more than enough).
2) How are these nonces to be appended chosen? Are they chosen randomly at every attempt or changed sequentially by adding 1 for example?
3) Does the bitcoin blockchain enforces the use of a specific algorithm for generating nonces or is it left to the miners to concoct their own algorithms as they see fit? (If enforced by the bitcoin block chain, I'd appreciate an explanation why)
4) If the choice is left to miners to generate nonces as they see fit, what is the best approach to generating these nonces available?
5) In a mining pools where many ASICs are hashing together, is there any coordination at the pool or at least at individual ASIC miner level to ensure no two ASIC chips are calculating the hash for the same nonce while trying to find the block? If not, what are the difficulties preventing such an implementation?
Thanks in advance and if there are any useful resources addressing these questions please share them especially ones describing the mining algorithm generating nonces.
submitted by BitcoinAsks to BitcoinMining [link] [comments]

Review and Prospect of Crypto Economy-Development and Evolution of Consensus Mechanism (1)

Review and Prospect of Crypto Economy-Development and Evolution of Consensus Mechanism (1)

https://preview.redd.it/7skleasc80a51.png?width=553&format=png&auto=webp&s=fc18cee10bff7b65d5b02487885d936d23382fc8
Table 1 Classification of consensus system
Source: Yuan Yong, Ni Xiaochun, Zeng Shuai, Wang Feiyue, "Development Status and Prospect of Blockchain Consensus Algorithm"
Figure 4 Evolution of consensus algorithm

Figure 4 Evolution of consensus algorithm
Source: Network data

Foreword
The consensus mechanism is one of the important elements of the blockchain and the core rule of the normal operation of the distributed ledger. It is mainly used to solve the trust problem between people and determine who is responsible for generating new blocks and maintaining the effective unification of the system in the blockchain system. Thus, it has become an everlasting research hot topic in blockchain.
This article starts with the concept and role of the consensus mechanism. First, it enables the reader to have a preliminary understanding of the consensus mechanism as a whole; then starting with the two armies and the Byzantine general problem, the evolution of the consensus mechanism is introduced in the order of the time when the consensus mechanism is proposed; Then, it briefly introduces the current mainstream consensus mechanism from three aspects of concept, working principle and representative project, and compares the advantages and disadvantages of the mainstream consensus mechanism; finally, it gives suggestions on how to choose a consensus mechanism for blockchain projects and pointed out the possibility of the future development of the consensus mechanism.
Contents
First, concept and function of the consensus mechanism
1.1 Concept: The core rules for the normal operation of distributed ledgers
1.2 Role: Solve the trust problem and decide the generation and maintenance of new blocks
1.2.1 Used to solve the trust problem between people
1.2.2 Used to decide who is responsible for generating new blocks and maintaining effective unity in the blockchain system
1.3 Mainstream model of consensus algorithm
Second, the origin of the consensus mechanism
2.1 The two armies and the Byzantine generals
2.1.1 The two armies problem
2.1.2 The Byzantine generals problem
2.2 Development history of consensus mechanism
2.2.1 Classification of consensus mechanism
2.2.2 Development frontier of consensus mechanism
Third, Common Consensus System
Fourth, Selection of consensus mechanism and summary of current situation
4.1 How to choose a consensus mechanism that suits you
4.1.1 Determine whether the final result is important
4.1.2 Determine how fast the application process needs to be
4.1.2 Determining the degree to which the application requires for decentralization
4.1.3 Determine whether the system can be terminated
4.1.4 Select a suitable consensus algorithm after weighing the advantages and disadvantages
4.2 Future development of consensus mechanism
Chapter 1 Concept and Function of Consensus Mechanism
1.1 Concept: The core rules for the normal operation of distributed ledgers
Since most cryptocurrencies use decentralized blockchain design, nodes are scattered and parallel everywhere, so a system must be designed to maintain the order and fairness of the system's operation, unify the version of the blockchain, and reward users maintaining the blockchain and punish malicious harmers. Such a system must rely on some way to prove that who has obtained the packaging rights (or accounting rights) of a blockchain and can obtain the reward for packaging this block; or who intends to harm , and will receive certain penalty. Such system is consensus mechanism.
1.2 Role: Solve the trust problem and decide the generation and maintenance of new blocks
1.2.1 Used to solve the trust problem between people
The reason why the consensus mechanism can be at the core of the blockchain technology is that it has formulated a set of rules from the perspective of cryptographic technologies such as asymmetric encryption and time stamping. All participants must comply with this rules. And theese rules are transparent, and cannot be modified artificially. Therefore, without the endorsement of a third-party authority, it can also mobilize nodes across the network to jointly monitor, record all transactions, and publish them in the form of codes, effectively achieving valuable information transfer, solving or more precisely, greatly improving the trust problem between two unrelated strangers who do not trust each other. After all, trusting the objective technology is less risky than trusting a subjective individual.
1.2.2 Used to decide who is responsible for generating new blocks and maintaining effective unity in the blockchain system
On the other hand, in the blockchain system, due to the high network latency of the peer-to-peer network, the sequence of transactions observed by each node is different. To solve this, the consensus mechanism can be used to reach consensus on transactions order within a short period of time to decide who is responsible for generating new blocks in the blockchain system, and to maintain the effective unity of the blockchain.
1.3 The mainstream model of consensus algorithm
The blockchain system is built on the P2P network, and the set of all nodes can be recorded as PP, generally divided into ordinary nodes that produce data or transactions, and"miner" nodes (denoted as M) responsible for mining operations, like verifying, packaging, and updating the data generated by ordinary nodes or transactions. The functions of the two types of nodes may be overlapped; miner nodes usually participate in the consensus competition process in general, and will select certain representative nodes and replace them to participant in the consensus process and compete for accounting rights in specific algorithms. The collection of these representative nodes is recorded as DD; the accounting nodes selected through the consensus process are recorded as AA. The consensus process is repeated in accordance with the round, and each round of the consensus process generally reselects the accounting node for the round . The core of the consensus process is the "select leader" and "accounting" two parts. In the specific operation process, each round can be divided into four stages: Leader election, Block generation, Data validation and Chain updating namely accounting). As shown in Figure 1, the input of the consensus process is the transaction or data generated and verified by the data node, and the output is the encapsulated data block and updated blockchain. The four stages are executed repeatedly, and each execution round will generate a new block.
Stage 1: Leader election
The election is the core of the consensus process, that is, the process of selecting the accounting node AA from all the miner node sets MM: we can use the formula f(M)→f(M)→AA to represent the election process, where the function ff represents the specific implementation of the consensus algorithm. Generally speaking, |A|=1,|A|=1, that is, the only miner node is finally selected to keep accounts.
Stage 2: Block generation
The accounting node selected in the first stage packages the transactions or data generated by all nodes PP in the current time period into a block according to a specific strategy, and broadcasts the generated new block to all miner nodes MM or their representative nodes DD. These transactions or data are usually sorted according to various factors such as block capacity, transaction fees, transaction waiting time, etc., and then packaged into new blocks in sequence. The block generation strategy is a key factor in the performance of the blockchain system, and it also exposes the strategic behavior of miners such as greedy transactions packaging and selfish mining.
Stage 3: Verification
After receiving the broadcasted new block, the miner node MM or the representative node DD will verify the correctness and rationality of the transactions or data encapsulated in the block. If the new block is approved by most verification/representative nodes, the block will be updated to the blockchain as the next block.
Stage 4: On-Chain
The accounting node adds new blocks to the main chain to form a complete and longer chain from the genesis block to the latest block. If there are multiple fork chains on the main chain, the main chain needs to be based on the consensus algorithm judging criteria to choose one of the appropriate fork chain as the main chain.
Chapter 2 The Origin of Consensus Mechanism
2.1 The two armies problems and the Byzantium generals problem
2.1.1 The two armies


Figure 2 Schematic diagram of the two armed forces
Selected from Yuan Yong, Ni Xiaochun, Zeng Shuai, Wang Feiyue, "Development Status and Prospect of Blockchain Consensus Algorithm", Journal of Automation, 2018, 44(11): 2011-2022
As shown in the figure, the 1st and 2nd units of the Blue Army are stationed on two sides of the slope, and cannot communicate remotely between each other. While the White Army is just stationed in the middle of the two Blue Army units. Suppose that the White Army is stronger than either of the two Blue Army units, but it is not as strong as the two Blue Army units combined. If the two units of the Blue Army want to jointly attack the White Army at the same time, they need to communicate with each other, but the White Army is stationed in the middle of them. It is impossible to confirm whether the messengers of two Blue Army units have sent the attack signal to each other, let alone the tampering of the messages. In this case, due to the inability to fully confirm with each other, ultimately no effective consensus can be reached between the two Blue Army units, rendering the "paradox of the two armies".
2.1.2 The Byzantine generals problem


Figure 3 Diagram of the Byzantine generals' problem
Due to the vast territory of the Byzantine roman empire at that time, in order to better achieve the purpose of defense, troops were scattered around the empire, and each army was far apart, and only messengers could deliver messages. During the war, all generals must reach an agreement, or decide whether to attack the enemy based on the majority principle. However, since it is completely dependent on people, if there is a situation where the general rebels or the messenger delivers the wrong message, how can it ensure that the loyal generals can reach agreement without being influenced by the rebels is a problem which was called the Byzantine problem.
The two armies problems and the Byzantine generals problem are all elaborating the same problem: in the case of unreliable information exchange, it is very difficult to reach consensus and coordinate action. The Byzantine general problem is more like a generalization of the "paradox of the two armies".
From the perspective of the computer network, the two armies problem and the Byzantine problem are common contents of computer network courses: the direct communication between two nodes on the network may fail, so the TCP protocol cannot completely guarantee the consistence between the two terminal networks. However, the consensus mechanism can use economic incentives and other methods to reduce this uncertainty to a level acceptable to most people.
It is precisely because of the two armies problem and the Byzantine problem that the consensus mechanism has begun to show its value.
2.2 Development history of consensus mechanism
2.2.1 Classification of consensus mechanism
Because different types of blockchain projects have different requirements for information recording and block generation, and as the consensus mechanism improves due to the development of blockchain technology, there are currently more than 30 consensus mechanisms. These consensus mechanisms can be divided into two categories according to their Byzantine fault tolerance performance: Byzantine fault tolerance system and non-Byzantine fault tolerance system.

Table 1 Classification of consensus mechanism
Source: Yuan Yong, Ni Xiaochun, Zeng Shuai, Wang Feiyue, "Development Status and Prospect of Blockchain Consensus Algorithm"
2.2.2 Development frontier of consensus mechanism
-Development of consensus algorithm
According to the proposed time of the consensus algorithm, we can see relatively clearly the development of the consensus algorithm.
Source: Network data

Figure 4 Development frontier of consensus algorithm

Figure 5 Historical evolution of blockchain consensus algorithm
Source: Yuan Yong, Ni Xiaochun, Zeng Shuai, Wang Feiyue, "Development Status and Prospect of Blockchain Consensus Algorithm"
The consensus algorithm has laid the foundation for the blockchain consensus mechanism. Initially, the research of consensus algorithms was mainly used by computer scientists and computer professors to improve the spam problem or conduct academic discussions.
For example, in 1993, American computer scientist and Harvard professor Cynthia Dwork first proposed the idea of proof of work in order to solve the spam problem; in 1997, the British cryptographer Adam Back also independently proposed to solve the spam problem by use of the mechanism of proof of work for hashing cash and published officially in 2002; in 1999, Markus Jakobsson officially proposed the concept of "proof of work", which laid the foundation for the subsequent design of Satoshi Nakamoto's Bitcoin consensus mechanism.
Next lecture: Chapter 3 Detailed Explanation of Consensus Mechanism Technology
CelesOS
As the first DPOW financial blockchain operating system, CelesOS adopts consensus mechanism 3.0 to break through the "impossible triangle". It provides both high TPS and decentralization. Committed to creating a financial blockchain operating system that embraces regulation, providing services for financial institutions and the development of applications on the regulation chain, and developing a role and consensus eco-system regulation level agreement for regulation.
The CelesOS team is committed to building a bridge between blockchain and regulatory agencies / finance industry. We believe that only blockchain technology that cooperates with regulators will have a bright future and strive to achieve this goal.
📷Website
https://www.celesos.com/
📷 Telegram
https://t.me/celeschain
📷 Twitter
https://twitter.com/CelesChain
📷 Reddit
https://www.reddit.com/useCelesOS
📷 Medium
https://medium.com/@celesos
📷 Facebook
https://www.facebook.com/CelesOS1
📷 Youtube
https://www.youtube.com/channel/UC1Xsd8wU957D-R8RQVZPfGA
submitted by CelesOS to u/CelesOS [link] [comments]

CYPHERIUM ENHACES BLOCKCHAIN TECHNOLOGY

OVERVIEW
Rarely has any technology such as blockchain attracted the public and media organisations. Institutions designed to catalyze the fourth industrial revolution are experimenting with technology, and investors have invested hundreds of millions of dollars in blockchain companies. This is a low-risk, experimental environment with error protection. Innovation is a combination of creativity and implementation. Ideas often must go through an evolutionary or cyclical phase before they are ready for commercialization. In fact, the cycle is so long that it is too expensive, inefficient in terms of time and money to generate and generate ideas, and in most cases almost never reaches commercial value. Thus, almost 99% of venture capital firms fail.
A fast growing technology that has come to enhance the blockchain technology is CYPHERIUM.

CHALLENGES FACING THE BLOCKCHAIN TECHNOLOGY
The Bitcoin framework is one of the most notable usage of blockchain innovations in circulated exchange based frameworks. In Bitcoin, each system hub seeks the benefit of putting away a lot of at least one exchanges in another square of the blockchain by comprehending a complex computational math issue, here and there alluded to as a mining verification of-work (POW). Under current conditions, a lot of exchanges is ordinarily put away in another square of the Bitcoin blockchain at a pace of around one new square like clockwork, and each square has an inexact size of one megabyte (MB). As needs be, the Bitcoin framework is dependent upon a looming versatility issue: as it were 3 to 7 exchanges can be handled every second, which is far underneath the quantity of exchanges handled in other exchange based frameworks, for example, the roughly 30,000 exchanges for each second in the Visa™ exchange framework. The most huge disadvantage of the Nakamoto accord is its absence of irrevocability. Conclusion implies once an exchange or an activity is performed on the blockchain, it is for all time recorded on the blockchain and difficult to turn around. This is fundamental to the wellbeing of money related repayment frameworks as exchanges must not be saved once they are made. For Bitcoin's situation, noxious on-screen characters can alter the exchange history given enough hash power, causing a twofold spending assault, given that there is sufficient motivator and money related practicality to complete such assaults. Given that mining gear leasing and botnets are at present predominant around the world, such an assault has become achievable.
Because of this absence of conclusiveness, Nakamoto accord must depend on additional measures, for example, confirmation of-work to forestall pernicious exercises. This hinders the capacity ofNakamoto accord to scale in light of the fact that a exchange must hang tight for various affirmations before coming to "probabilistic absolution".
In this way, wellbeing isn't ensured by Nakamoto agreement, and so as to secure the system, each exchange must experience extra an ideal opportunity to process. For Bitcoin's situation, an exchange isn't considered last until in any event six affirmations. Since Bitcoin can just process a couple of exchanges every second, the exchange cost is preposterously high, making it unreasonable for little installments like shopping for food or eatery feasting. This extraordinarily frustrates Bitcoin's utilization as an installment strategy in this present reality.

CYPHERIUM SOLUTIONS
Cypherium's exclusive algorithm, CypherBFT conquers burdens of the earlier craftsmanship by giving a circulated exchange framework including a gathering of validator hubs that are known to each other in a system however are undefined to the next system hubs in the system. As utilized thus, the gathering of validator hubs might be alluded to as a "Board of trustees" of validator hubs. In a few explanations, the framework reconfigures at least one validator hubs in the Committee dependent on the consequences of confirmation of-work (POW) challenges. As per some uncovered epitomes, a system hub that isn't as of now a validator hub in the Committee might be added to the Committee on the off chance that it effectively finishes a POW challenge. In such an occasion, the system hub may turn into another validator hub in the Committee, supplanting a current validator hub. In elective epitomes, a system hub may become another validator hub in the Committee dependent on a proof-of-stake (POS) accord. In yet another epitome, a system hub may turn into another validator hub in the Committee dependent on a verification of-authority (POA) agreement. In other elective exemplifications, a system hub may turn into a new validator hub in the Committee dependent on a mix of any of POW, POA, and POS accord.

In some revealed exemplifications, the new validator hub replaces a validator hub in the Committee. The substitution might be founded on a foreordained guideline known by all the hubs in the system. For model, the new validator hub may supplant the most established validator hub in the Committee. As indicated by another model, the new validator hub may supplant a validator hub that has been resolved to have gone disconnected, become bargained (e.g., hacked), fizzled (e.g., because of equipment breakdown), or in any case is inaccessible or not, at this point trusted. In the praiseworthy exemplifications, the circulated framework expect that for an adaptation to non-critical failure of f hubs, the Committee incorporates at any rate 3f +1 validator hubs.
Since the validator hubs in the Committee might be every now and again supplanted, for instance, contingent upon the measure of time required to finish the POW challenges, it is hard for vindictive outsiders to identify the total arrangement of validator hubs in the Committee at some random time.

BENEFITS OF CYPHERIUM BLOCKCHAIN TECHNOLOGY
Cypherium runs its exclusive CypherBFT accord, tied down by the HotStuff calculation, and can genuinely offer moment irrevocability for its system clients. With its HotStuff-based structure, the CypherBFT's runtime keeps going just 20-30 milliseconds (ms). A few affirmations are all that is required to for all time acknowledge a proposed obstruct into the blockchain, and it just takes 90ms for these affirmations to come to pass, making the procedure essentially quicker than the two-minutes required by EOS.
Cypherium's CypherBFT, which additionally uses HotStuff, doesn't have to pick between responsiveness and linearity. Cypherium's double blockchain structure incorporates the velocities of a dag, however its review for clients can occur a lot more straightforward and quicker, which adds to the accessibility of data and makes the data more decentralized.
As per some revealed epitomes, the validator hubs in the Committee may get exchange demands from other system hubs, for instance, in a P2P organize. The Committee may incorporate at any rate one validator hub that fills in as a "Pioneer" validator hub; the other validator hubs might be alluded to as "Partner" validator hubs. The Leader hub might be changed occasionally, on request, or inconsistently by the individuals from the Committee. At the point when any validator hub gets another exchange demand from a non-validator hub in the system, the exchange solicitation might be sent to the entirety of the validator hubs in the Committee. Further to the unveiled epitomes, the Pioneer hub facilitates with the other Associate validator hubs to arrive at an accord of an attitude (e.g., acknowledge or dismiss) for an exchange square containing the exchange solicitation and communicates the accord to the whole P2P arrange. In the event that the accord is to acknowledge or in any case approve the exchange demand, the mentioned exchange might be included another square of a blockchain that is known to in any event a portion of the system hubs in the system.
In conclusion, CYPHERIUM'S distributed smart-contracts block-chain is ideal for a good number of use cases which include (but not limited to):
Finance
Messaging
Voting
Notarization
Digital Agreements (Contracts)
Secure data storage
A.I (Artificial Intelligence)
IoT (Internet of Things
To know more about CYPHERIUM kindly visit the following links:
WEBSITE: https://cypherium.io/
GITHUB: https://github.com/cypherium
WHITEPAPER: https://github.com/cypherium/patent/blob/maste15224.0003%20-%20FINAL%20Draft%20Application%20(originally%200003%20invention%201)%20single%20chain%20in%20pipeline.pdf
TELEGRAM: https://t.me/cypherium_supergroup
TWITTER: http://twitter.com/cypheriumchain
FACEBOOK: https://www.facebook.com/CypheriumChain/
AUTHOR: Nwali Jennifer
submitted by iphygurl to BlockchainStartups [link] [comments]

Dive Into Tendermint Consensus Protocol (I)

Dive Into Tendermint Consensus Protocol (I)
This article is written by the CoinEx Chain lab. CoinEx Chain is the world’s first public chain exclusively designed for DEX, and will also include a Smart Chain supporting smart contracts and a Privacy Chain protecting users’ privacy.
longcpp @ 20200618
This is Part 1 of the serialized articles aimed to explain the Tendermint consensus protocol in detail.
Part 1. Preliminary of the consensus protocol: security model and PBFT protocol
Part 2. Tendermint consensus protocol illustrated: two-phase voting protocol and the locking and unlocking mechanism
Part 3. Weighted round-robin proposer selection algorithm used in Tendermint project
Any consensus agreement that is ultimately reached is the General Agreement, that is, the majority opinion. The consensus protocol on which the blockchain system operates is no exception. As a distributed system, the blockchain system aims to maintain the validity of the system. Intuitively, the validity of the blockchain system has two meanings: firstly, there is no ambiguity, and secondly, it can process requests to update its status. The former corresponds to the safety requirements of distributed systems, while the latter to the requirements of liveness. The validity of distributed systems is mainly maintained by consensus protocols, considering the multiple nodes and network communication involved in such systems may be unstable, which has brought huge challenges to the design of consensus protocols.

The semi-synchronous network model and Byzantine fault tolerance

Researchers of distributed systems characterize these problems that may occur in nodes and network communications using node failure models and network models. The fail-stop failure in node failure models refers to the situation where the node itself stops running due to configuration errors or other reasons, thus unable to go on with the consensus protocol. This type of failure will not cause side effects on other parts of the distributed system except that the node itself stops running. However, for such distributed systems as the public blockchain, when designing a consensus protocol, we still need to consider the evildoing intended by nodes besides their failure. These incidents are all included in the Byzantine Failure model, which covers all unexpected situations that may occur on the node, for example, passive downtime failures and any deviation intended by the nodes from the consensus protocol. For a better explanation, downtime failures refer to nodes’ passive running halt, and the Byzantine failure to any arbitrary deviation of nodes from the consensus protocol.
Compared with the node failure model which can be roughly divided into the passive and active models, the modeling of network communication is more difficult. The network itself suffers problems of instability and communication delay. Moreover, since all network communication is ultimately completed by the node which may have a downtime failure or a Byzantine failure in itself, it is usually difficult to define whether such failure arises from the node or the network itself when a node does not receive another node's network message. Although the network communication may be affected by many factors, the researchers found that the network model can be classified by the communication delay. For example, the node may fail to send data packages due to the fail-stop failure, and as a result, the corresponding communication delay is unknown and can be any value. According to the concept of communication delay, the network communication model can be divided into the following three categories:
  • The synchronous network model: There is a fixed, known upper bound of delay $\Delta$ in network communication. Under this model, the maximum delay of network communication between two nodes in the network is $\Delta$. Even if there is a malicious node, the communication delay arising therefrom does not exceed $\Delta$.
  • The asynchronous network model: There is an unknown delay in network communication, with the upper bound of the delay known, but the message can still be successfully delivered in the end. Under this model, the network communication delay between two nodes in the network can be any possible value, that is, a malicious node, if any, can arbitrarily extend the communication delay.
  • The semi-synchronous network model: Assume that there is a Global Stabilization Time (GST), before which it is an asynchronous network model and after which, a synchronous network model. In other words, there is a fixed, known upper bound of delay in network communication $\Delta$. A malicious node can delay the GST arbitrarily, and there will be no notification when no GST occurs. Under this model, the delay in the delivery of the message at the time $T$ is $\Delta + max(T, GST)$.
The synchronous network model is the most ideal network environment. Every message sent through the network can be received within a predictable time, but this model cannot reflect the real network communication situation. As in a real network, network failures are inevitable from time to time, causing the failure in the assumption of the synchronous network model. Yet the asynchronous network model goes to the other extreme and cannot reflect the real network situation either. Moreover, according to the FLP (Fischer-Lynch-Paterson) theorem, under this model if there is one node fails, no consensus protocol will reach consensus in a limited time. In contrast, the semi-synchronous network model can better describe the real-world network communication situation: network communication is usually synchronous or may return to normal after a short time. Such an experience must be no stranger to everyone: the web page, which usually gets loaded quite fast, opens slowly every now and then, and you need to try before you know the network is back to normal since there is usually no notification. The peer-to-peer (P2P) network communication, which is widely used in blockchain projects, also makes it possible for a node to send and receive information from multiple network channels. It is unrealistic to keep blocking the network information transmission of a node for a long time. Therefore, all the discussion below is under the semi-synchronous network model.
The design and selection of consensus protocols for public chain networks that allow nodes to dynamically join and leave need to consider possible Byzantine failures. Therefore, the consensus protocol of a public chain network is designed to guarantee the security and liveness of the network under the semi-synchronous network model on the premise of possible Byzantine failure. Researchers of distributed systems point out that to ensure the security and liveness of the system, the consensus protocol itself needs to meet three requirements:
  • Validity: The value reached by honest nodes must be the value proposed by one of them
  • Agreement: All honest nodes must reach consensus on the same value
  • Termination: The honest nodes must eventually reach consensus on a certain value
Validity and agreement can guarantee the security of the distributed system, that is, the honest nodes will never reach a consensus on a random value, and once the consensus is reached, all honest nodes agree on this value. Termination guarantees the liveness of distributed systems. A distributed system unable to reach consensus is useless.

The CAP theorem and Byzantine Generals Problem

In a semi-synchronous network, is it possible to design a Byzantine fault-tolerant consensus protocol that satisfies validity, agreement, and termination? How many Byzantine nodes can a system tolerance? The CAP theorem and Byzantine Generals Problem provide an answer for these two questions and have thus become the basic guidelines for the design of Byzantine fault-tolerant consensus protocols.
Lamport, Shostak, and Pease abstracted the design of the consensus mechanism in the distributed system in 1982 as the Byzantine Generals Problem, which refers to such a situation as described below: several generals each lead the army to fight in the war, and their troops are stationed in different places. The generals must formulate a unified action plan for the victory. However, since the camps are far away from each other, they can only communicate with each other through the communication soldiers, or, in other words, they cannot appear on the same occasion at the same time to reach a consensus. Unfortunately, among the generals, there is a traitor or two who intend to undermine the unified actions of the loyal generals by sending the wrong information, and the communication soldiers cannot send the message to the destination by themselves. It is assumed that each communication soldier can prove the information he has brought comes from a certain general, just as in the case of a real BFT consensus protocol, each node has its public and private keys to establish an encrypted communication channel for each other to ensure that its messages will not be tampered with in the network communication, and the message receiver can also verify the sender of the message based thereon. As already mentioned, any consensus agreement ultimately reached represents the consensus of the majority. In the process of generals communicating with each other for an offensive or retreat, a general also makes decisions based on the majority opinion from the information collected by himself.
According to the research of Lamport et al, if there are 1/3 or more traitors in the node, the generals cannot reach a unified decision. For example, in the following figure, assume there are 3 generals and only 1 traitor. In the figure on the left, suppose that General C is the traitor, and A and B are loyal. If A wants to launch an attack and informs B and C of such intention, yet the traitor C sends a message to B, suggesting what he has received from A is a retreat. In this case, B can't decide as he doesn't know who the traitor is, and the information received is insufficient for him to decide. If A is a traitor, he can send different messages to B and C. Then C faithfully reports to B the information he received. At this moment as B receives conflicting information, he cannot make any decisions. In both cases, even if B had received consistent information, it would be impossible for him to spot the traitor between A and C. Therefore, it is obvious that in both situations shown in the figure below, the honest General B cannot make a choice.
According to this conclusion, when there are $n$ generals with at most $f$ traitors (n≤3f), the generals cannot reach a consensus if $n \leq 3f$; and with $n > 3f$, a consensus can be reached. This conclusion also suggests that when the number of Byzantine failures $f$ exceeds 1/3 of the total number of nodes $n$ in the system $f \ge n/3$ , no consensus will be reached on any consensus protocol among all honest nodes. Only when $f < n/3$, such condition is likely to happen, without loss of generality, and for the subsequent discussion on the consensus protocol, $ n \ge 3f + 1$ by default.
The conclusion reached by Lamport et al. on the Byzantine Generals Problem draws a line between the possible and the impossible in the design of the Byzantine fault tolerance consensus protocol. Within the possible range, how will the consensus protocol be designed? Can both the security and liveness of distributed systems be fully guaranteed? Brewer provided the answer in his CAP theorem in 2000. It indicated that a distributed system requires the following three basic attributes, but any distributed system can only meet two of the three at the same time.
  1. Consistency: When any node responds to the request, it must either provide the latest status information or provide no status information
  2. Availability: Any node in the system must be able to continue reading and writing
  3. Partition Tolerance: The system can tolerate the loss of any number of messages between two nodes and still function normally

https://preview.redd.it/1ozfwk7u7m851.png?width=1400&format=png&auto=webp&s=fdee6318de2cf1c021e636654766a7a0fe7b38b4
A distributed system aims to provide consistent services. Therefore, the consistency attribute requires that the two nodes in the system cannot provide conflicting status information or expired information, which can ensure the security of the distributed system. The availability attribute is to ensure that the system can continuously update its status and guarantee the availability of distributed systems. The partition tolerance attribute is related to the network communication delay, and, under the semi-synchronous network model, it can be the status before GST when the network is in an asynchronous status with an unknown delay in the network communication. In this condition, communicating nodes may not receive information from each other, and the network is thus considered to be in a partitioned status. Partition tolerance requires the distributed system to function normally even in network partitions.
The proof of the CAP theorem can be demonstrated with the following diagram. The curve represents the network partition, and each network has four nodes, distinguished by the numbers 1, 2, 3, and 4. The distributed system stores color information, and all the status information stored by all nodes is blue at first.
  1. Partition tolerance and availability mean the loss of consistency: When node 1 receives a new request in the leftmost image, the status changes to red, the status transition information of node 1 is passed to node 3, and node 3 also updates the status information to red. However, since node 3 and node 4 did not receive the corresponding information due to the network partition, the status information is still blue. At this moment, if the status information is queried through node 2, the blue returned by node 2 is not the latest status of the system, thus losing consistency.
  2. Partition tolerance and consistency mean the loss of availability: In the middle figure, the initial status information of all nodes is blue. When node 1 and node 3 update the status information to red, node 2 and node 4 maintain the outdated information as blue due to network partition. Also when querying status information through node 2, you need to first ask other nodes to make sure you’re in the latest status before returning status information as node 2 needs to follow consistency, but because of the network partition, node 2 cannot receive any information from node 1 or node 3. Then node 2 cannot determine whether it is in the latest status, so it chooses not to return any information, thus depriving the system of availability.
  3. Consistency and availability mean the loss of the partition tolerance: In the right-most figure, the system does not have a network partition at first, and both status updates and queries can go smoothly. However, once a network partition occurs, it degenerates into one of the previous two conditions. It is thus proved that any distributed system cannot have consistency, availability, and partition tolerance all at the same time.

https://preview.redd.it/456x2blv7m851.png?width=1400&format=png&auto=webp&s=550797373145b8fc1471bdde68ed5f8d45adb52b
The discovery of the CAP theorem seems to declare that the aforementioned goals of the consensus protocol is impossible. However, if you’re careful enough, you may find from the above that those are all extreme cases, such as network partitions that cause the failure of information transmission, which could be rare, especially in P2P network. In the second case, the system rarely returns the same information with node 2, and the general practice is to query other nodes and return the latest status as believed after a while, regardless of whether it has received the request information of other nodes. Therefore, although the CAP theorem points out that any distributed system cannot satisfy the three attributes at the same time, it is not a binary choice, as the designer of the consensus protocol can weigh up all the three attributes according to the needs of the distributed system. However, as the communication delay is always involved in the distributed system, one always needs to choose between availability and consistency while ensuring a certain degree of partition tolerance. Specifically, in the second case, it is about the value that node 2 returns: a probably outdated value or no value. Returning the possibly outdated value may violate consistency but guarantees availability; yet returning no value deprives the system of availability but guarantees its consistency. Tendermint consensus protocol to be introduced is consistent in this trade-off. In other words, it will lose availability in some cases.
The genius of Satoshi Nakamoto is that with constraints of the CAP theorem, he managed to reach a reliable Byzantine consensus in a distributed network by combining PoW mechanism, Satoshi Nakamoto consensus, and economic incentives with appropriate parameter configuration. Whether Bitcoin's mechanism design solves the Byzantine Generals Problem has remained a dispute among academicians. Garay, Kiayias, and Leonardos analyzed the link between Bitcoin mechanism design and the Byzantine consensus in detail in their paper The Bitcoin Backbone Protocol: Analysis and Applications. In simple terms, the Satoshi Consensus is a probabilistic Byzantine fault-tolerant consensus protocol that depends on such conditions as the network communication environment and the proportion of malicious nodes' hashrate. When the proportion of malicious nodes’ hashrate does not exceed 1/2 in a good network communication environment, the Satoshi Consensus can reliably solve the Byzantine consensus problem in a distributed environment. However, when the environment turns bad, even with the proportion within 1/2, the Satoshi Consensus may still fail to reach a reliable conclusion on the Byzantine consensus problem. It is worth noting that the quality of the network environment is relative to Bitcoin's block interval. The 10-minute block generation interval of the Bitcoin can ensure that the system is in a good network communication environment in most cases, given the fact that the broadcast time of a block in the distributed network is usually just several seconds. In addition, economic incentives can motivate most nodes to actively comply with the agreement. It is thus considered that with the current Bitcoin network parameter configuration and mechanism design, the Bitcoin mechanism design has reliably solved the Byzantine Consensus problem in the current network environment.

Practical Byzantine Fault Tolerance, PBFT

It is not an easy task to design the Byzantine fault-tolerant consensus protocol in a semi-synchronous network. The first practically usable Byzantine fault-tolerant consensus protocol is the Practical Byzantine Fault Tolerance (PBFT) designed by Castro and Liskov in 1999, the first of its kind with polynomial complexity. For a distributed system with $n$ nodes, the communication complexity is $O(n2$.) Castro and Liskov showed in the paper that by transforming centralized file system into a distributed one using the PBFT protocol, the overwall performance was only slowed down by 3%. In this section we will briefly introduce the PBFT protocol, paving the way for further detailed explanations of the Tendermint protocol and the improvements of the Tendermint protocol.
The PBFT protocol that includes $n=3f+1$ nodes can tolerate up to $f$ Byzantine nodes. In the original paper of PBFT, full connection is required among all the $n$ nodes, that is, any two of the n nodes must be connected. All the nodes of the network jointly maintain the system status through network communication. In the Bitcoin network, a node can participate in or exit the consensus process through hashrate mining at any time, which is managed by the administrator, and the PFBT protocol needs to determine all the participating nodes before the protocol starts. All nodes in the PBFT protocol are divided into two categories, master nodes, and slave nodes. There is only one master node at any time, and all nodes take turns to be the master node. All nodes run in a rotation process called View, in each of which the master node will be reelected. The master node selection algorithm in PBFT is very simple: all nodes become the master node in turn by the index number. In each view, all nodes try to reach a consensus on the system status. It is worth mentioning that in the PBFT protocol, each node has its own digital signature key pair. All sent messages (including request messages from the client) need to be signed to ensure the integrity of the message in the network and the traceability of the message itself. (You can determine who sent a message based on the digital signature).
The following figure shows the basic flow of the PBFT consensus protocol. Assume that the current view’s master node is node 0. Client C initiates a request to the master node 0. After the master node receives the request, it broadcasts the request to all slave nodes that process the request of client C and return the result to the client. After the client receives f+1 identical results from different nodes (based on the signature value), the result can be taken as the final result of the entire operation. Since the system can have at most f Byzantine nodes, at least one of the f+1 results received by the client comes from an honest node, and the security of the consensus protocol guarantees that all honest nodes will reach consensus on the same status. So, the feedback from 1 honest node is enough to confirm that the corresponding request has been processed by the system.

https://preview.redd.it/sz8so5ly7m851.png?width=1400&format=png&auto=webp&s=d472810e76bbc202e91a25ef29a51e109a576554
For the status synchronization of all honest nodes, the PBFT protocol has two constraints on each node: on one hand, all nodes must start from the same status, and on the other, the status transition of all nodes must be definite, that is, given the same status and request, the results after the operation must be the same. Under these two constraints, as long as the entire system agrees on the processing order of all transactions, the status of all honest nodes will be consistent. This is also the main purpose of the PBFT protocol: to reach a consensus on the order of transactions between all nodes, thereby ensuring the security of the entire distributed system. In terms of availability, the PBFT consensus protocol relies on a timeout mechanism to find anomalies in the consensus process and start the View Change protocol in time to try to reach a consensus again.
The figure above shows a simplified workflow of the PBFT protocol. Where C is the client, 0, 1, 2, and 3 represent 4 nodes respectively. Specifically, 0 is the master node of the current view, 1, 2, 3 are slave nodes, and node 3 is faulty. Under normal circumstances, the PBFT consensus protocol reaches consensus on the order of transactions between nodes through a three-phase protocol. These three phases are respectively: Pre-Prepare, Prepare, and Commit:
  • The master node of the pre-preparation node is responsible for assigning the sequence number to the received client request, and broadcasting the message to the slave node. The message contains the hash value of the client request d, the sequence number of the current viewv, the sequence number n assigned by the master node to the request, and the signature information of the master nodesig. The scheme design of the PBFT protocol separates the request transmission from the request sequencing process, and the request transmission is not to be discussed here. The slave node that receives the message accepts the message after confirming the message is legitimate and enter preparation phase. The message in this step checks the basic signature, hash value, current view, and, most importantly, whether the master node has given the same sequence number to other request from the client in the current view.
  • In preparation, the slave node broadcasts the message to all nodes (including itself), indicating that it assigns the sequence number n to the client request with the hash value d under the current view v, with its signaturesig as proof. The node receiving the message will check the correctness of the signature, the matching of the view sequence number, etc., and accept the legitimate message. When the PRE-PREPARE message about a client request (from the main node) received by a node matches with the PREPARE from 2f slave nodes, the system has agreed on the sequence number requested by the client in the current view. This means that 2f+1 nodes in the current view agree with the request sequence number. Since it contains information from at most fmalicious nodes, there are a total of f+1 honest nodes that have agreed with the allocation of the request sequence number. With f malicious nodes, there are a total of 2f+1 honest nodes, so f+1represents the majority of the honest nodes, which is the consensus of the majority mentioned before.
  • After the node (including the master node and the slave node) receives a PRE-PREPARE message requested by the client and 2f PREPARE messages, the message is broadcast across the network and enters the submission phase. This message is used to indicate that the node has observed that the whole network has reached a consensus on the sequence number allocation of the request message from the client. When the node receives 2f+1 COMMIT messages, there are at least f+1 honest nodes, that is, most of the honest nodes have observed that the entire network has reached consensus on the arrangement of sequence numbers of the request message from the client. The node can process the client request and return the execution result to the client at this moment.
Roughly speaking, in the pre-preparation phase, the master node assigns a sequence number to all new client requests. During preparation, all nodes reach consensus on the client request sequence number in this view, while in submission the consistency of the request sequence number of the client in different views is to be guaranteed. In addition, the design of the PBFT protocol itself does not require the request message to be submitted by the assigned sequence number, but out of order. That can improve the efficiency of the implementation of the consensus protocol. Yet, the messages are still processed by the sequence number assigned by the consensus protocol for the consistency of the distributed system.
In the three-phase protocol execution of the PBFT protocol, in addition to maintaining the status information of the distributed system, the node itself also needs to log all kinds of consensus information it receives. The gradual accumulation of logs will consume considerable system resources. Therefore, the PBFT protocol additionally defines checkpoints to help the node deal with garbage collection. You can set a checkpoint every 100 or 1000 sequence numbers according to the request sequence number. After the client request at the checkpoint is executed, the node broadcasts messages throughout the network, indicating that after the node executes the client request with sequence number n, the hash value of the system status is d, and it is vouched by its own signature sig. After 2f+1 matching CHECKPOINT messages (one of which can come from the node itself) are received, most of the honest nodes in the entire network have reached a consensus on the system status after the execution of the client request with the sequence numbern, and then you can clear all relevant log records of client requests with the sequence number less than n. The node needs to save these2f+1 CHECKPOINTmessages as proof of the legitimate status at this moment, and the corresponding checkpoint is called a stable checkpoint.
The three-phase protocol of the PBFT protocol can ensure the consistency of the processing order of the client request, and the checkpoint mechanism is set to help nodes perform garbage collection and further ensures the status consistency of the distributed system, both of which can guarantee the security of the distributed system aforementioned. How is the availability of the distributed system guaranteed? In the semi-synchronous network model, a timeout mechanism is usually introduced, which is related to delays in the network environment. It is assumed that the network delay has a known upper bound after GST. In such condition, an initial value is usually set according to the network condition of the system deployed. In case of a timeout event, besides the corresponding processing flow triggered, additional mechanisms will be activated to readjust the waiting time. For example, an algorithm like TCP's exponential back off can be adopted to adjust the waiting time after a timeout event.
To ensure the availability of the system in the PBFT protocol, a timeout mechanism is also introduced. In addition, due to the potential the Byzantine failure in the master node itself, the PBFT protocol also needs to ensure the security and availability of the system in this case. When the Byzantine failure occurs in the master node, for example, when the slave node does not receive the PRE-PREPARE message or the PRE-PREPARE message sent by the master node from the master node within the time window and is thus determined to be illegitimate, the slave node can broadcast to the entire network, indicating that the node requests to switch to the new view with sequence number v+1. n indicates the request sequence number corresponding to the latest stable checkpoint local to the node, and C is to prove the stable checkpoint 2f+1 legitimate CHECKPOINT messages as aforementioned. After the latest stable checkpoint and before initiating the VIEWCHANGE message, the system may have reached a consensus on the sequence numbers of some request messages in the previous view. To ensure the consistency of these request sequence numbers to be switched in the view, the VIEWCHANGE message needs to carry this kind of the information to the new view, which is also the meaning of the P field in the message. P contains all the client request messages collected at the node with a request sequence number greater than n and the proof that a consensus has been reached on the sequence number in the node: the legitimate PRE-PREPARE message of the request and 2f matching PREPARE messages. When the master node in view v+1 collects 2f+1 VIEWCHANGE messages, it can broadcast the NEW-VIEW message and take the entire system into a new view. For the security of the system in combination with the three-phase protocol of the PBFT protocol, the construction rules of the NEW-VIEW information are designed in a quite complicated way. You can refer to the original paper of PBFT for more details.

https://preview.redd.it/x5efdc908m851.png?width=1400&format=png&auto=webp&s=97b4fd879d0ec668ee0990ea4cadf476167a2948
VIEWCHANGE contains a lot of information. For example, C contains 2f+1 signature information, P contains several signature sets, and each set has 2f+1 signature. At least 2f+1 nodes need to send a VIEWCHANGE message before prompting the system to enter the next new view, and that means, in addition to the complex logic of constructing the information of VIEWCHANGE and NEW-VIEW, the communication complexity of the view conversion protocol is $O(n2$.) Such complexity also limits the PBFT protocol to support only a few nodes, and when there are 100 nodes, it is usually too complex to practically deploy PBFT. It is worth noting that in some materials the communication complexity of the PBFT protocol is inappropriately attributed to the full connection between n nodes. By changing the fully connected network topology to the P2P network topology based on distributed hash tables commonly used in blockchain projects, high communication complexity caused by full connection can be conveniently solved, yet still, it is difficult to improve the communication complexity during the view conversion process. In recent years, researchers have proposed to reduce the amount of communication in this step by adopting aggregate signature scheme. With this technology, 2f+1 signature information can be compressed into one, thereby reducing the communication volume during view change.
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