Not long ago, Vitalik posted an article entitled “Why sharding is great: demystifying the technical properties” (https://vitalik.ca/general/2021/ 04/07/sharding.html, there are obvious traces of Chinese machine translation, it is recommended to read the English version), technically explain the specific attributes and sacrifices provided by Ethereum sharding. The article mentioned: “Sharding is the future of Ethereum’s scalability. It will be the key to helping the ecosystem support thousands of transactions per second and allowing most parts of the world to regularly use the platform at an affordable cost.”

The article is a good article, especially by defining the specific attributes of Ethereum sharding, which separates the line from “rogue sharding” (the original “technology with very different and usually much weaker security attributes”).

Although Baker admires the strength of V God Painting Cake and agrees that safe and reliable sharding technology is the inevitable development direction of blockchain technology in the future, he still feels unhappy about some of the errors in the article.

The core logic of the article is that God V believes that the three attributes of scalability, decentralization, and security cannot be obtained simultaneously through “simple” technology, which is the so-called “Impossible Triangle”. “, and sharding technology can solve these problems at the same time, so “sharding is great.” This logic seems to make sense at first glance, but after thinking about it, it is specious. There are three main loopholes: “simple” technology, “impossible triangle”, and the necessity of fragmentation.

望梅止渴的以太坊分片(Sharding) The first is the argument that “simple” technology cannot obtain three attributes at the same time. There is no definition of what kind of technology can be called “simple”. In actual discussion, the concept is changed into three “easy solutions”: the traditional single chain including Bitcoin and Ethereum is composed of a few High-throughput blockchains maintained by nodes (about EOS and consortium chains), as well as multi-chain ecosystems (Pokadot and other “rogue shards” that do not guarantee security, etc.).

The logical problem with this argument is that “simple” does not mean “easy”, and the example argument after changing the concept is more like picking up the persimmon because it does not exhaust all the possibilities.

A similar logic has been seen in a joke before-“How to prove that all odd numbers are prime numbers? Let’s take a look: 3 is a prime number, 5 is a prime number, and 7 is also a prime number. The proof is over.

“The second type of blockchain with high throughput (“High-TPS chains”) seems to be equated with the small number of nodes in the concept of V God, making the mistake of circular argumentation. In short, here is The discussion definitely did not consider Conflux, which can achieve thousands of TPS throughput on thousands of consensus nodes. Perhaps V God’s definition of “simple” here can directly draw a line according to the effect, which can solve the “Impossible Triangle”. “” are all classified as “not simple” technology, so as to ensure that the logical rigor is invincible.

Secondly, the so-called “impossible triangle” is also a long-standing misconception. Although it is often compared with the CAP theorem of distributed systems, in fact, the “blockchain impossible triangle” has never been theoretically proven, at best it can only be regarded as a “hypothesis” or “conjecture”. This logic of equating “I can’t do it by myself” with “Impossible” has a sense of constipation and complaining that the earth is not attractive.

Fortunately, God V seems to realize that mentioning the advantages of the “Impossible Triangle” Ethereum sharding makes no sense, so I secretly added a premise in this article-“If you insist on using simple technology, then Cannot get three attributes at the same time”.

I don’t know when I can officially change the term “blockchain impossible triangle” to “blockchain simple technology can’t do the triangle temporarily” to face up, and it is recommended to add a line of small characters “‘simple technology’ means that it cannot be obtained at the same time. These three attributes of blockchain technology”.

Finally, this article is not enough to support the necessity and urgency of sharding technology. Sharding can certainly break the “Impossible Triangle” and solve the performance problems faced by Ethereum. But this is only a condition of sufficiency, and it cannot explain why the sharding technology must be used, or even why the “impossible triangle” must be broken.

In the description of the “impossible triangle”, the scalability requirement is that the processing power of the entire blockchain consensus system exceeds the processing power of an ordinary consumer-grade PC or laptop as a single node. In the long run, this goal is ultimately to be achieved, but judging from the current actual situation of Ethereum, this goal is very ambitious. With current computer performance, a single machine can handle thousands or even tens of thousands of transactions per second, while Ethereum can only process no more than 50 transactions, which is far from reaching the bottleneck. Sharding based on the current performance of Ethereum is like a child who has not yet understood elementary school mathematics and must learn advanced mathematics.

望梅止渴的以太坊分片(Sharding)

Therefore, even if sharding can solve the problems faced by Ethereum, it does not mean that sharding must be used to solve it. Compared with when the concept of Ethereum sharding was first proposed, there are now many ready-made solutions including high-performance consensus algorithms such as Conflux and second-layer expansion solutions such as Rollup. If you insist on doing fragmentation again, it’s a bit like going to the dark one by one.

In addition to the loopholes in the core logic, the sacrifice of the sharding itself in terms of security, reliability, and performance is also very obvious. God has already said it in more detail in the article, so I won’t repeat it here.

Only one point is corrected here: sharding will inevitably reduce the user experience, and the problem of increasing the waiting time for confirming users is unavoidable, and it is not only in the scheme of fraud proof. Although proof technologies such as ZK-SNARK can greatly improve the verification efficiency of transactions and ensure that transactions can be quickly confirmed after they are on the chain, such technologies without exception require a longer time to generate proofs. Therefore, from the user’s point of view, the cost of using ZK-SNARK technology to reduce the waiting time after the transaction is on the chain is to increase the time to wait for the proof to be generated before being on the chain, and the overall experience may not be much improved. Those who hope that ZK-SNARK can solve the delay problem caused by fragmentation should review the story of the past.

In summary, Roots believes that Ethereum’s sharding technology is like the plum in the story of Wangmei quenching thirst. It can be inspiring but has little practical significance. If you keep thinking about the plums in the distance, and turn a blind eye to the streams around you, you will probably only die of thirst on the road.