V God takes you to re-understand Ethereum

Decentralized permissionless network

The Ethereum network does not want to be the kind of network that relies on super nodes, which is where the Ethereum network differs from other networks. Ethereum should be a fully functioning system without relying on any supercomputers, ideally a bunch of home laptops running the Ethereum network. As some Bitcoin believers have said, if the network is over-centralized and controlled by a few institutions, it may eventually go in an unsatisfactory direction.

EHT2 wants to create a PoS ecosystem in which anyone can participate, which is why Ethereum has not been inclined to super nodes, nor does it believe in the assumption of "majority honesty", which is very similar to the idea of ​​​​Bitcoin . In the network, it is better for participants to verify the chain by themselves and try not to trust miners, because miners are not necessarily honest.

In general:

2. ETH2 guarantees that most ordinary users can directly participate in the writing of the chain;

3. At the same time, it is guaranteed that most ordinary users can directly read the data of the chain without relying on the trusted API;

4. Allow most ordinary users to participate in the consensus of the chain.

If you combine 2, 3, and 4 together, you will get a blockchain that is highly resistant to auditing and social and political attacks.

Do people really care about these qualities that Ethereum sticks to?

There are many competing products of Ethereum that have compromised on decentralization, permissionlessness, and the conservative nature of Ethereum, but in essence, the centralized path can be very efficient in the short term, but it will have serious side effects in the long run. For example, a typical example is Steemit, which was acquired by Justin Sun. Excessive centralization will eventually lead to community forks. EOS has also seen bribing attacks. Ultimately, the core participants in the centralized chain will collude to erode the rights and interests of ordinary users.

From the perspective of governance, if the voting governance power of a chain is controlled by those large currency holders, it will be very dangerous in the long run.

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Other communities that hold on to these qualities

Coda is very good. They are trying to create a chain that can use zero-knowledge proof, so that zk snark can directly verify the chain instead of individuals, and nodes cannot directly do evil. Mimblewimble and ETC are also good. Although ETC does not implement sharding, it tries to maintain a decentralized expansion plan.

However, for projects that adhere to these characteristics as a selling point, they are not as popular as projects that focus on other concepts. Because insisting on these characteristics is bound to mean that the stories that can be told are limited, but if stories are told using other concepts, then many things can be told. Although there will be very few chains featuring these qualities, Vitalik believes that this part of the project will eventually be successful.

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Long-awaited PoS and sharding

Before the release of ETH1.0, PoS and sharding have been identified as the direction to improve ETH. Vitalik answered the question of how the community chooses the technical direction in the early stage.

As early as 2015, the community basically reached a consensus on the technical path of PoS and sharding. The occurrence of the DAO fork reinforces this. Those who opposed PoS and sharding also opposed the DAO fork, so they finally chose to support ETC.

It did take a while to be convinced that PoS and sharding were the right technology direction. Looking back at the original blog about Slasher, you will find that at the beginning of this article: Slasher is preparing for the possible implementation of PoS in the future. In January 2014, Vitalik was not sure whether there was a PoS Essential defects.

After 2014, another issue has become the focus of heated discussions, and that is the "Nothing at Stake" issue of the PoS system, which Vitalik answered in "Proof of Stake: How I Learned to Love Weak Subjectivity". Although PoS cannot have exactly the same characteristics as PoW, PoS can absorb the advantages of the PoW system as much as possible.

During the 16 to 17 years, people conducted in-depth research on other consensus algorithms, and finally figured out how to apply the security model of PoW to PoS.

For sharding, the main problem is how to choose the best security model. In 2015, Vitalik and the technical community began to try random sampling (Random Sampling), which is a breakthrough in applying sharding technology to the chain. In 2017, the community completed a breakthrough in the proof of data availability, which allowed the shard chain to remain safe even in the case of "majority dishonesty". After these explorations, we found that sharding is a feasible solution.

When we released ETH1.0 in 2015, we thought that PoS should be realized in one to one and a half years, but real time showed that the ideas at that time were too optimistic, but everyone was very confident at the time.

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Looking at the Token Distribution Mechanism from the Monetary Policy of Ethereum

Afterwards, Vitalik and the technical team believed that although PoS is necessary and feasible, PoW may be the most equal and fair distribution method. From 2010 to 2013, PoW was considered the most democratic token distribution model, and even became a major selling point of BTC at that time: as long as you turn on your computer, you can get some BTC. This may also be the most attractive point of BTC at that time. But in fact, PoW cannot form a long-term stable technical equilibrium. When mining is very profitable, specialized mining machines will appear. BTC is the best example, from the GPU revolution to the FPGA revolution to the ASIC revolution. For Ethereum, although its PoW algorithm has special resistance to ASICs to ensure the fairness of ETH mining, as time goes on, GPU-based systems will become more and more money-oriented. and resources, it may eventually cause ETH HASH to suffer ASIC risks.

PoW V.S PoS

So PoW will go to ASIC anyway. Although ETH is mined using GPUs, professional ETH miners drive amateur miners out of the market.

This is a problem with the PoW mining mechanism. BTC already has the problem of chaebol rule, and it is only a matter of time for ETH. No matter how the algorithm is improved, it cannot avoid moving to ASIC.

The design challenge of the token distribution mechanism is to ensure its neutrality. The advantage of the PoW system is that people know what the algorithm looks like, anyone can do verification, and anyone can participate. But the method of distribution through social media like Ripple is very unfair. First, not everyone can participate in it. Second, hackers can register 10,000 accounts in order to get tokens. You don’t want to see the underlying public chain. The token distribution model is like this. For the PoS system, its essence is to redistribute tokens to token holders and allow token holders to maintain network security. Apart from the existing PoS and PoW token distribution mechanisms, there is no more neutral token distribution mechanism now. If there is a slight change in the distribution mechanism of PoW and PoS, there may be other disputes.

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Many people think that the disadvantage of PoS is that as long as you participate in the network to get tokens at the time of creation, you can participate in the network forever as a pledger, but the miners in PoW need to update their hardware facilities all the time.

First of all, the PoW market is still very young and may be often affected by the outside world, but these problems may no longer be a problem for the mature PoW market. But regarding the thermodynamic limit problem often discussed by BTC miners, when the cost of producing a hash answer is as low as the limit, the efficiency cannot be improved any more, and this will indeed become a problem that PoW cannot solve. Secondly, for POS, if you have 32 ETH, you can become a validator yourself and get more tokens. If you don’t have that much ETH, you can also get ETH by staking with other people. In the PoW system, you must have enough start-up funds to buy mining machines, otherwise it is impossible for you to mine. In this way, PoS also eliminates the problem of excessive concentration of wealth. Finally, the return of POS is generally lower than that of POW, and the more people involved, the lower the return.

So in general, PoW has its advantages, while PoS is easier to participate but the benefits will be lower.

The most important point is what if someone owns 51% of the coins or 51% of the computing power. Compared with PoW, PoS gives the community more rescue solutions. For POW, you can only watch the 51% attack happen. Maybe you can soft fork, but the attacker can continue to attack the forked chain. Vitalik calls this attack "SPAWN CAMP ATTACK". To solve the problem, just Only the POW algorithm can be changed, but this not only hurts the attacker, but also hurts ordinary miners. When the PoW algorithm is changed, no one will have ASIC mining machines with the new algorithm for a period of time. If the attacker monopolizes the CPU GPU market, the attacker can continue to launch attacks, and then the chain will be over.

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Why participate in the pledge of ETH2

Vitalik sees this as an announcement to be an Ethereum citizen, and to be incentivized by income.

If you can't be a verification block node, you should also try to participate in the network to verify the Ethereum network. The reason is mentioned in "A Philosophy of Blockchain Validation". It is not necessary to verify everything on the chain. You can selectively verify, such as verifying data availability, verifying fraud proofs, or even running a light node. It also prevents you from trusting a certain node. This kind of autonomous behavior is not only beneficial to users themselves, but will ultimately benefit the entire Ethereum ecosystem.

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Why Ethereum chooses sharding

(Rhythm Note: The concept of sharding comes from the concept of database partition table. The so-called sharding is actually to put data on different databases and hosts, so that data can be processed in parallel and improve processing efficiency. In the blockchain , each slice processes the transactions in its own slice, so as to achieve the effect of expansion.)

As early as 2014, Vitalik and the Ethereum community began to explore and research on sharding. Relevant researchers agreed at the beginning that every transfer on the chain needs to be verified by every node is a very stupid thing, and Ethereum should use a more efficient way to ensure chain security.

Vitalik has been greatly inspired by studying computer science over the past few years. During the learning process, Vitalik deeply realized that when you complicate an efficient algorithm a little bit, you can achieve the best efficiency.

However, this sorting algorithm is not the most efficient. Smarter algorithms may be similar to merge sorting, quick sorting, and some other classification algorithms. The steps required for these algorithms are no longer O(N^2), but is O(LogN).

For example, if you have a sequence of 100 numbers, since 100 is a three-digit number, the required processing steps are 100*3, that is, 300 steps. When you understand the operation logic of these algorithms, you will feel that these algorithms are very concise and clear from a mathematical point of view. Although these algorithms are slightly more complicated than ordinary algorithms, their efficiency has been greatly improved.

The initial blockchain is like a common algorithm, each node verifies every transfer, although it is simple and easy to understand, it is very inefficient. What the blockchain needs now is a slightly more complex, but more efficient algorithm. Sharding may be such an algorithm. In the world of sharding, verifiers do not need to verify everything, but only some, which is very efficient.

But in this case, how to defend against 1% attacks (the attacker concentrates computing power on a certain part of a chain and makes the attacked part unable to operate normally)? After research and exploration, researchers have now come up with several very ingenious ways to defend against this attack.

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Doubts people have about sharding

There are still many people who believe that sharding is not feasible, and the points of criticism are mainly divided into two levels:

Secondly, they deeply question the various assumptions in sharding. They believe that these assumptions may make the system more fragile when the actual system is running.