Vitalik Buterin said that through Rollup, 90% of the data and 99% of the calculations can be placed off-chain, and then 10% of the data and 1% of the calculations can be placed on the chain, so the scalability can be increased by about 100 times. The combination of Rollups and sharding will achieve a 10,000-fold increase in scalability.
Original title: Dialogue with Vitalik Buterin: The combination of sharding and Rollups will bring a 10,000-fold increase in capacity. Source: Lex Fridman Podcast
Editor: South Wind
Recently, Ethereum co-founder Vitalik Buterin participated in an interview with blog host Lex Fridman. In the interview, he talked about cryptocurrency, regulation, MEV (miner extractable value), Ethereum 2.0, PoS security, Layer 2 (Rollups ), Grand Merger, Polygon, etc. The interview lasts about 3 hours. This article is compiled from some content of this interview. For the complete content, please refer to the video of this interview. The following is part of the content of this interview:
Lex Fridman : Shiba Inu was created in 2020, imitating Dogecoin, you are given 50% of the total supply of Shiba, and then you “destroy” 90% of the gift, worth 6.7 billion US dollars, and you will 10% ( At the time, it was worth 1.2 billion U.S. dollars) to the Indian COVID-19 Relief Fund (Indian COVID-19 Relief Fund), expressing that he did not want to enjoy such great power.
Vitalik : Let me first talk about the background of these coins and the story of giving me these coins. Dogecoin was originally created in the form of “joke” around 2014, and people didn’t take it seriously at the beginning. I invested USD 25,000 in Doge in 2016. At that time, I was thinking about how to explain to my mother that I invested money in these Dogecoins. The only interesting thing about this coin is that it has a dog’s logo. Finally, it proved This is one of my best investments. Then at the end of 2020, Elon Musk began to discuss Degecoin, and then its market value skyrocketed to 50 billion US dollars. It skyrocketed many times, for example, the first time it rose from 0.8 cents to about 7 cents, which happened within 1 day. of. I remember when I was still in Singapore and saw its price skyrocketed by more than 100%. Then I thought the Dege I held was worth a lot of money, and then I sold half of the Doge I held and got 4.3 million US dollars. Then donated it directly. A few hours later, its price dropped from about 7 cents to 4 cents. So I sold Doge at a high point, and at the time I thought I was a very powerful trader. Later Doge went from 4 cents to 7 cents and then 50 cents. Doge has become a very influential thing, and many people who have not heard of Ethereum have heard of Doge. This is something I did not expect.
Then some people think that since Doge’s market value can reach 50 billion US dollars, you should be able to reach billions of US dollars for other coins that imitate it. I think this is the idea of people who created Shiba. But they directly gave me 50% of Shiba supply, but they were not the first project to give me coins. At about the end of 2020, there was an oracle project Tellor. I think this project should be a competitor of Chainlink. I remember that they directly sent me 50,000 dollars worth of coins, and they advertised everywhere, “Look! Vitalik holds it.” Our Token, he is one of our supporters.” After realizing this, I publicly sold their Token through Uniswap and ended the rumor.
People like Shiba are also smarter. Instead of sending coins to my address, they sent coins to my cold wallet. Then I noticed that many people were discussing this coin. The coins I donated were also worth billions of dollars. After I got my cold wallet key, I started to sell some coins and donated some directly to them. Several charities. I actually sold 80% of Shiba and donated the ETH obtained to some organizations, and then directly donated 20% of Shiba, including the Indian COVID Relief Fund and other institutions.
Lex Fridman : What do you think about the regulation of blockchain? What is the best case and the worst case?
Vitalik : The best scenario is that the blockchain continues to prosper, and then we found a way to expand the blockchain so that people can do all kinds of things on the blockchain, that is, all the incredible things that people have been talking about. , And then there are many good applications running on the blockchain, such as DAOs that allow people to interact in a better way, and allow artists to better benefit, etc., and then get enough public support to let People realize that cryptocurrency can do a lot of good things, and there are other innovation potentials that need to be understood.
The worst case is that people suddenly think that this technology is being used by some bad people, but I don’t think the government can prevent the existence of blockchain, but they have the ability to marginalize it, such as banning all exchanges and banning all Mainstream employers accept and use cryptocurrency payments to make their impact even smaller. Obviously I want good things to happen.
Lex Fridman : Let’s talk about Ethereum 2.0. How will Eth2 make Ethereum more scalable, safer and more sustainable?
Vitalik : In fact, we no longer emphasize the title Eth2 recently. The reason behind it is that we initially envisioned a very big and red vision, thinking that all good things will happen at the same time: a brand new blockchain and a brand new one. Agreement. Later, we slowly adjusted the roadmap to a more gradual form. Both PoS and sharding occurred over time, as did all functions and features, even though ordinary Ethereum users felt It is a seamless experience, which may be more complicated than the previous hard fork upgrade, but it is not that complicated from the user’s point of view.
It was once considered to be the two flagship functions of Ethereum 2.0, but now it is only considered to be the flagship function of the next Ethereum evolution, namely PoS and sharding. PoS is a consensus algorithm or consensus mechanism. The consensus mechanism is the way in which network nodes upload to the chain in which block or transaction to ensure that once a block is uploaded to the chain, it cannot be reversed.
The existing blockchains such as Bitcoin and Ethereum use PoW. Basically, there are many computers (nodes) in this network to reach a consensus on which block to accept, and sometimes two blocks will be released at the same time, so it is necessary A consensus is reached on the order of the blocks, so a “voting game” is needed. But whoever has a higher voting weight cannot pass the “one person, one vote” method, because a bad guy may have 100 billion virtual computers on his computer, so he has 10 billion virtual nodes, and then maybe It owns 99% of the network nodes and controls everything on the network.
In order to prevent this from happening, PoW and PoS both determine your voting weight proportionally based on how much economic resources you contribute to the network. Then in PoW, you have to prove how many economic resources you have, that is, how many computers you own and run them 24*7. This method does work, because if you want to attack the network, you need to invest in more computers and More capital and electricity, the cost is very high.
In PoS, unlike PoW, which contributes computing power 24*7, you only need to pledge a certain amount of currency into the system as an economic resource. I like PoS for many years because it needs to consume less resources. It does not need to purchase mining equipment from manufacturers and consume a lot of energy like PoW. PoS only needs to be run on a commonly used computer. Run the PoS validator node on the ordinary computer you are using. Therefore, this method should be less resource-intensive and not burden the environment. Another reason is that based on PoS, the blockchain does not need to pay as much as PoW to those who maintain the network (miners). Currently, Bitcoin and Ethereum provide about 4% of the total supply to miners every year. Ethereum newly issues about 4.7 million ETH each year, and the current total supply is 115 million ETH. But through PoS, we expect that the annual increase will be about 500,000 to 1 million ETH, which means that the total supply will not increase too fast.
Lex Fridman : How do you think PoS is safe?
Vitalik : I think PoS is very safe, because if you want to successfully attack the Ethereum network, then basically you need to have the amount of ETH pledged in the entire network. For example, now we have 5 million ETH pledged (in the beacon In the chain), then you (the attacker) need to own 5 million ETH and join the network. These ETHs are worth about 15 billion U.S. dollars. I think this is more expensive than attacking the Bitcoin network. Secondly, PoS needs to recover from the attack. It is easier than PoW. In PoS, we have many measures against attacks. For example, we have an automatic slashing (penalty) mechanism to destroy the coins pledged by the perpetrator, and the community can also cope with it by coordinating soft forks (successful ) Attack, the attacker will lose a lot of coins in the new chain.
Lex Fridman : Some people think that MEV (miner extractable value) is a threat facing Ethereum. What is MEV and how to deal with it?
Vitalik : Both PoW and PoS have MEV (Miner Extractable Value) problems, which can also be called Block Proposer Extractable Value (PBEV, that is, the block proposer can extract value). The basic meaning is that if you have the ability to package which transactions into the block in what order, then you can use this advantage to obtain economic benefits, not only through transaction fees, such as by running or then Following others’ transactions to make a profit, the block proposer can get a certain percentage of the profit.
The reason why this phenomenon is a challenge is that it sometimes reduces the user experience and makes the user’s transaction not in a favorable position, and the greater risk is the economies of scale that MEV brings to miners or verifiers, which may lead to PoW Mining or PoS verification is more centralized. Therefore, the ecosystem has paid attention to MEV, and projects such as Flashbots are already in progress. This is indeed a risk, but we are already doing something to deal with it.
Lex Fridman : Let’s talk about the concept of expansion, specifically Layer 1, Layer 2, the interaction between the two, and the concept of fragmentation.
Vitalik : There are two paradigms for expanding the blockchain , namely Layer 1 expansion and Layer 2 expansion. The L1 extension is to enable the blockchain itself to process more transactions through some mechanisms, although the blockchain itself has some performance limitations; the L2 extension does not change L1, but creates a protocol on the chain to inherit the security of L1 At the same time, many things are done off-chain, so more scalability can be obtained. In Ethereum, the most popular L2 paradigm is Rollups, and the most popular L1 expansion paradigm is sharding.
Lex Fridman : One of the ways to expand the blockchain is to increase the block size. Before I talk about Sharding, can I talk about the block size dispute?
Vitalik : This is a trade-off between better writing to the blockchain (that is, transactions on the blockchain) and better reading of the blockchain (that is, letting nodes verify that the transactions on the chain are correct). In terms of decentralization, both are equally important. If the cost of reading a block chain is high, it means that people need to trust a small number of nodes, and these nodes can change the rules of the block chain without the consent of others; and if a block The writing (transaction) of the chain is very expensive, so everyone will move to a very centralized secondary system.
Therefore, I think this needs to strike a balance between the two. Leaning towards one of them will lead to the development of the blockchain in an unhealthy direction. I think there are two main reasons for the current Bitcoin block size of 1 M. One is that they think that it is really important to be able to read the block chain; the other is that many people are maintaining it without hard forks. in principle. A larger block size means that the blockchain will be more centralized, because fewer people will be able to run nodes, and it may also lead to a hard fork.
Lex Fridman : So what is sharding? What are the characteristics of sharding?
Vitalik : Sharding does not increase the parameters like increasing the block size, but changes the architecture of the blockchain so that a single node in the network only needs to store part of the data of the entire network and process part of the transactions. The challenge of adopting this model and applying it to the blockchain is that the blockchain is not only to disperse the data in the network, but to reach a consensus on the data dispersed in the network and to ensure that the consensus data is correct . Therefore, there will be such a paradox. For example, if you need a blockchain that can process 10,000 transactions per second, but each computer node in the blockchain can only process 100 transactions per second, how can a single computer What about trusting other computers while verifying all transactions?
There are many ways to achieve this. For example, the method is to randomly shuffle (disrupt) the validators. For example, there are 10,000 validators (stakers) in a PoS chain. For simplicity, we assume that each validator pledges The same amount of coins, and then randomly scramble the validators, 100 of them (form a committee) are assigned to verify a block, the other 100 are assigned to verify another block, and so on . Then the effective information broadcast method is that a certain 100 verifiers will sign a block when verifying it to show that they agree with the validity of the block, and then all the signatures of the block will be aggregated into one signature and Will be broadcast to other verifiers in the network, then other verifiers only need to verify the signature, without directly verifying the transaction in the block. When other verifiers see this signature, they do not directly believe that the block is valid, but believe that most verifiers in the block agree that the block is valid . Therefore, if I believe that most of the validators of the block are honest (because these validators are randomly assigned, the attacker cannot put all the validator nodes under his control into the same committee, that is to say The nodes controlled by the attacker will also be randomly disrupted), then illegal blocks will not be included in the blockchain. This is a simple form of sharding.
There are other more sensible forms, such as the concept of zk-SNARKs, which is a zero-knowledge proof, which is a concept of generating encrypted proofs, which means that a proof is generated by running some complex operations on a piece of data. If this kind of proof is generated, for example, if you see a zk-SNARKs proof that a certain block is valid, then you can believe that the block is valid. There is also a type called data availability sampling, which allows you to be sure that the data in the block has been released. Basically, if you stack these methods, then you can create a blockchain system that allows individual participants to believe that everything that happens on the chain is correct without having to verify it themselves. This is Sharding.
Lex Fridman : As far as I know, Ethereum is proposed to implement 64 shards. How does this achieve expansion? Is this number fixed? This is to achieve its scalability to compete with credit cards or Visa?
Vitalik : Over time, the number of 64 shards can be increased through hard forks, and in theory, 1024 shard chains can be realized. More shard chains will bring challenges. For example, there needs to be a logic to check and manage all these shards. If there are too many shards, it will bring higher costs, but you can still improve slightly. of. And another thing we are doing is to combine Sharding with Rollups .
Lex Fridman : Oh, Rollups. Let’s now discuss the concept of L2,
Vitalik : The basic idea of Rollup is that users send transactions to a central aggregator. In theory, anyone can become an aggregator in a Rollup, which is a permissionless model. What Aggregator does is that they will remove all transaction data that is not related to the update state, and then retain and compress the data needed to update the state, so only these small compressed data need to be published on the chain, without publishing All transaction data. The amount of data published on the chain may be reduced tenfold.
Also, calculations are not performed on the chain, but are calculated off the chain. There are two ways to do this, one of which is zk-Rollup, which is to provide a zk-SNARK proof to indicate “I performed the calculation, this is the proof of my calculated hash”, and then the proof Submit it to the chain, and then everyone verifies the proof without verifying all these transactions; the other method is Optimistic Rollup, which basically means that one person first claims that the result of the transaction that he believes is correct, and then another person can Express opposition and claim that the transaction results are not the same. If there is such a disagreement, then the data of the entire block needs to be published and verified on the chain, and the wrong party will lose a lot of money.
Therefore, through Rollup, 90% of the data and 99% of the calculation can be placed off-chain, and then 10% of the data and 1% of the calculation can be placed on the chain, so the scalability can be increased by about 100 times . Now these systems are already online for some applications, such as Loopring, a payment platform based on zk-Rollup. You can deposit funds into the Loopring system to conduct transactions with very low transaction fees, such as 5 cents (instead of 5 US dollars). Although Rollups on Ethereum currently only support a few applications, it is expected that in a few months there will be Rollups fully compatible with Ethereum. Therefore, the combination of Rollups and sharding can achieve a 10,000-fold increase in scalability, resulting in thousands of tps.
Lex Fridman : So this scalability can process a large number of transactions faster and at a lower cost.
