On the evening of February 28th, the founders of Bihu Gulu and Vitalik conducted an AMA on the second-layer technology of Ethereum Rollup. The content of this article is provided by"walk"secondary title
The following is a brief summary of last night's content, Enjoy:
Gulu: Let me first share with you why I chose this topic today. We are also doing research on Rollup Layer 2 technology. I think Rollup's second-layer technology, I believe, will become the mainstream application scenario of Ethereum in the future. In the future, the Dapp that everyone may use will be mainly used on the second layer of Rollup, not on the first layer. This is a very important topic.
There are rumors that some Rollup Layer 2 networks will be launched on Ethereum in March. Just in time for the third anniversary of Bihuo, I would like to share it with you. Vitalik will exchange questions about the second layer and Rollup through face-to-face asking and answering.
Vitalik is not in China. He is in North America time. It is the morning to share with us. He is really dedicated. Vitalik will try to communicate with everyone in Chinese throughout the process.
If you have any questions before Vitalik came, I can also answer them. (Rhythm Note: The following are community questions, Gulu answers)
1. Will the second-tier network increase the value of Bitcoin?
It is the second-tier network of Ethereum, which has little relationship with Bitcoin. Of course, there is also wBTC on Ethereum, but I don’t think it is a very direct inertial system.
2. Which Rollup solution is Gulu optimistic about?
Leave that question to Vitalik. What I see more is Optimistic Rollup. Its advantage is that applications on one layer can be migrated relatively easily. On one layer, Defi or other applications can basically reuse the code on Optimistic Rollup. After the audit on the first floor, the more mature codes and applications used by everyone can be directly moved to the second floor, and the ecology (establishment) will be faster.
3. Will the expansion of Ethereum have an impact on Polkadot?
I think that if the second layer of Ethereum develops, it will put pressure on all public chains. Because the current ecology of Ethereum is actually the best, and it is not a little bit better than other public chains.
The main problem with Ethereum right now is throughput. This was mentioned on my last stream with Dovey. At that time, many people did not think that throughput was the biggest problem. In fact, when I communicated with many people in the industry, I felt that the biggest problem on Ethereum was the throughput problem two years ago. Of course, many people in the Ethereum ecosystem think so too.
The expansion of Ethereum has been going on for a long time. Initially, the capacity was expanded through the state channel. The Raiden Network was derived. The problem with state channels is that users themselves have to become both services and users. The status channel needs to observe the status by itself, and needs to send the status to the underlying public chain when it is over. It must be wrong that the user in the state channel is both the user and the server. It is unlikely to require users to provide their own services and use them at the same time.
Later, Plashma was derived from the state channel, and the service is provided by some nodes. Users only need to care about using it. But Plashma has a problem. When the data is not given to you, how do you trust Plashma's nodes, and how do you know whether they are doing evil or not. This was a very difficult problem before. For the data on the second layer, when the node does not give it to you, you don't know what it is doing.
In Plashma's assumption, if the user still wants to detect the status of the network. When users do not get new data, they have to escape from the Plashma network, because users should assume that these nodes of Plashma are doing evil. So Plashma also has a transition period of hours or days, which is the challenge period. This is actually similar to the current Optimistic Rollup.
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Vitalik is online
Gulu: Sorry, the Chinese community is too enthusiastic today. I'll still make a short opening statement.
Why did you choose this topic today? It is because we are also watching the research of Rollup, and we are also planning to choose a Rollup on the second layer of Ethereum to start a decentralized transaction protocol. During the research process, I feel more and more that the second layer based on Rollup will become the mainstream of Ethereum in the future. It is possible that at some time in the future, when everyone uses Ethereum, they are mainly using the second layer of Ethereum. Such a transformation is a qualitative change for Ethereum itself and for the entire ecology. I think that the Rollup-based two-layer technology will bring about dramatic changes to the entire industry.
So I am very, very optimistic about the second-tier technology. That's why I chose this topic today.
Everyone is so enthusiastic that sometimes I can't even see the questions in the comment area. Today's topic is mainly completed by asking me to answer. Everyone asks questions, and Vitalik answers them. I believe you have read a lot of articles about Rollup recently.
Without further ado, let's get to the point. I will start by throwing bricks and starting jade. My question is also a concern of many development teams who want to develop on the second layer of Rollup.
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1. My question is: How is the security on Rollup compared to one layer? For example, if we have made a MYKEY smart wallet, can users deploy the smart wallet account on the second floor instead of on the first floor? For example, will the security of Optimistic Rollup be enough? Furthermore, in the future, if the contract for issuing tokens is also deployed directly on the second layer instead of on the first layer?
Vitalik: This question is particularly important. The security of a Rollup involves two issues. One is application security, and the other is asset security. Asset security means that if you have coins or assets in Rollup, whether the coins or assets will be lost or whether someone will attack Rollup and steal your coins; system security means that if you have an application on the second layer , if Rollup is attacked or there is a problem, even if the currency is still there, the application cannot do anything.
The security of assets is basically no problem. There is absolutely no security issue in ZK Rollup. Each Rollup block has a zero-knowledge proof, and there is no possibility of putting an unverified block in. There may be problems in Optimistic Rollup, but it is a range problem. If there is a problematic block, and someone can find it before the new block is generated, there is no problem. So I think asset security is not a big problem.
The security of the system itself may be the bigger issue. The current Rollup is relatively simple. The current Rollup uses a server to package blocks. If the server crashes, Rollup cannot be used for a period of time.
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Gulu: Can I understand that at this stage, it is still not recommended to directly deploy contracts such as smart wallets on the second layer, or put the currency directly on the second layer? Maybe it's ok in the second stage?
Vitalik: I think we can start putting some applications on the second layer now. There are many blockchain applications that do not need to run 24 hours a day, even if there are security issues, there will not be much loss. For example, many non-financial applications can do this. For example, use the blockchain to make some records, or NFT can already be placed in Rollup.
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2. Gulu: Let’s answer the first question from the community: besides fast transfer speed and low fees, the second layer of Ethereum should be used for other purposes?
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3. Gulu: The second question: Use ETH as a service fee to capture value. After a large number of transactions are transferred to Rollup, can the value of ETH be linked to the ecological value for a long time? I think it's a very good question. In fact, some second-tier GAS payments can be paid with other tokens besides ETH. I thought it might be this question.
Vitalik: After Rollup, the project party will still pay the transaction fees on the Ethereum chain. It is possible that users will have many methods (using other tokens to pay on the second layer) to pay their transaction fees, but choose the application project side on Rollup, the nodes on Ethereum still need to send Ethereum transactions, or need to pay Ethereum Transaction fees on FangChain.
What is certain is that if you need to pay 100 yuan for the current transaction, you may only need to pay 1 yuan after Rollup. Of course different applications will have different efficiencies. Sometimes the GAS is reduced by a factor of 100, sometimes by a factor of 500.
Because Rollup is more efficient and less expensive. So more transactions will be generated on Rollup. If there are 1 million transactions in Ethereum every day, each transaction needs to pay a transaction fee of 100 yuan. If everyone moves to Rollup, there may be a daily transaction volume of 100 million, so even if each transaction is a transaction fee of 1 block, the total transaction fee may be higher.
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4. Gulu: There is a question related to the question just now: Will the second floor plunder the value of the first floor later? Will it develop into a new public chain?
Vitalik: It's always possible. But I don't think the Ethereum community would like it if it was done. The community will move to other projects very quickly. Our community is stricter now. If you are working on a Rollup project, they will look at your code and see the details to know whether you are really doing Rollup. If it is true, they will go, if you say you are Rollup, but it is not at all, they will know and use other projects (vote with their feet).
So if a Rollup project starts to say that it is Rollup, but moves to other chains (making its own public chain), the threat to the project itself will be great.
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Gulu: If Rollup becomes its own independent public chain, the community can actually fork. The second layer of Rollup is public data, and anyone can continue to run this Rollup.
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5. Gulu: Layer 2, the expansion plan of Ethereum, is about to come out, which means that the project Loopring has been launched. Is Vitalik optimistic about it?
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6. Gulu: After the implementation of the London plan in July, how much will each transaction be reduced to?
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7. Gulu: The next question: How to compare the difference between Optimistic Rollup and Arbitrum Rollup.
Vitalik: Both teams are very good. I think the biggest technical difference between them is that Arbitrum's mechanism is directly manipulated by EVM. The application can run the code directly on Arbitrum. But Optimistic made its own EVM in its own contract. So instead of running your EVM code directly, you will use the built-in virtual machine, and the contract will run in the first, second, and third steps.
The advantage of the Arbitrum method is that it can support more VMs, now it can support EVM, and later it can support more programming languages. But the disadvantage is that sending a transaction in Optimistic may be valid or invalid, and you can directly know the result. But on Arbitrum, the protocol requires you to send a transaction first, and another user sends another transaction. The transaction may have to be repeated three or five times, and then the built-in virtual machine will be asynchronous, and it will be based on the last step to judge whether you are right or someone else is right. So this mechanism is more complicated and requires more code, so I worry that there will be more security risks and problems in this method. But this method is more general and can support more programming languages.
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8. Gulu: In terms of economic incentives, will both Optimistic Rollup and Arbitrum Rollup have their own native tokens?
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9. Gulu: The next question is that the Optimistic Rollup scheme is currently used only temporarily, and the ZK Rollup scheme will eventually be transitioned to in the future, right?
Vitalik: ZK Rollup has a longer-term future. Because its mechanics and economic agreement will be simpler. But I don't know how long this long-term future will be, it may be 5 years, 10 years. The current zero-knowledge proof technology is relatively complex and novel. It takes a lot of time to make a fully ZK virtual machine to make sure it is safe.
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10. Gulu: If the launch of Ethereum 2.0 is too slow, it is easy to be surpassed by other public chains during this period. Why can't it be released sooner?
Vitalik: The short-term solution to the problem of expansion does not really need 2.0, but Rollup.
Now Ethereum may support 15 to 45 transactions per second depending on the transaction. After everyone moves to Rollup, the number of transactions may increase by 100 times. Depending on the specific transaction type, TPS may reach 1500-4000 transactions per second.
So even without sharding and Ethereum 2.0, Rollup's technology can solve all current expansion problems. But in the long run, there are many public chains with a TPS of 4,000. But if more people use blockchain in the future and blockchain becomes more mainstream, we definitely need more TPS. Because the current mainstream centralized services require 10,000 or 100,000 or more transactions per second. So in the long run, fragmentation is still particularly needed.
The biggest value of 2.0 is that POW is completely moved to POS, and we can get many advantages of POS. In our previous plan, the first step was to start the 2.0 chain. We have already done this step. The POS chain has been running for three months and there are almost no problems; the second step is our original plan. Sharding, the third step is Merge the current Ethereum 1.0 chain and 2.0 chain.
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11. Gulu: There are already several Rollup networks online. But there is not much money for user migration. Is there any way to guide users to migrate there?
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The second question is that there is not much infrastructure ecology related to Rollup. For example, we haven't solved the problem of transactions between different Rollups. If I have some coins in ZKsync, how can I move them to Loopring? First, you need to withdraw the currency from the second layer of ZKsync to the bottom layer of Ethereum, and then transfer it to the second layer account of Loopring. If this is done, will transaction fees be particularly high?
Another problem is that there are many services that do not yet support Rollup. For example, there is no exchange that directly supports ZKsync or Loopring as Dpos. But there will be changes on this point, and I already know that many exchanges are researching Rollup.
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12. Gulu: The following question is a question from a user. With more and more applications on the second layer of Rollup, there will be more and more projects on the second layer, and it will be equally crowded. In the end, the problem of high handling fees could not be solved.
Vitalik: If the space on the Rollup is not enough, we will have fragmentation, which will expand the data space of the Rollup. But I think the scalability of the second layer will not be a problem. When we need more scalability, the first step is to establish shards, and then we can always upgrade the shards. This is not my worry.
The problem I am worried about is that if the Gas fee of Layer one will always be extremely high, there are many things you can implement in one Rollup, but if you need to conduct transactions in different Rollups, you need to pay a particularly high Gas fee, There will be unexpected situations that require you to call the underlying. At this time, the transaction fee will become particularly high. This is a real problem. But we're also working on a lot of ways to reduce that.
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13. Gulu: The following question, which Rollup projects are you optimistic about?
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14. Gulu: I see that you have asked a lot of questions about ERP-1559. I thought we could take a moment to talk about your thoughts on ERP-1559. Now there are many people who strongly disagree or strongly agree, and it is controversial in the community. Ask Vitalik to share your thoughts.
Vitalik: EPR-1559 is very important to the Ethereum ecosystem. It can solve the bottom-level problems of many users. For example, users need to choose how high the transaction fee is. If you want to realize the transaction quickly, you need to pay a high transaction fee. If you choose a lower transaction fee, there will be risks. The transaction needs to wait for one minute, three minutes, one hour or one day. EPR-1559 addresses issues like these. (Make transaction fees more predictable)
EPR-1559 has many other benefits as well. One of the often mentioned benefits is that most of the transaction fees will be destroyed. In this case, if the total amount of transaction fees in Ethereum is more, the total amount of ETH will decrease. The Ethereum economic model will become more sustainable.
Many people now criticize Ethereum and believe that Bitcoin has a total limit of 21 million. But Ethereum ETH has no upper limit, so they think ETH will be unstable. But if there are more transactions after EPR-1559, it is possible that the total amount of ETH will decrease, or the total amount will only increase a little (from inflation to moderate deflation-walking note). This change in the economic model is also what many people are looking forward to.
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15. Gulu: Everyone also asked a lot of questions about Ethereum’s competitors and other public chains. I think everyone wants to ask what will happen to the competitive relationship between Ethereum's second-layer technology and other smart contract platforms?
Vitalik: This one is hard to predict. I think the difference between Ethereum and many competing chains is that the TPS of competing chains will be higher. When they promote themselves, they will say that the Ethereum chain is very slow, our chain has a higher TPS, and the blockchain is faster. But their choice has the disadvantage that their chains will be more centralized.
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16. Gollum: Let's ask one last question. If the layered network is very successful, is it still necessary to do sharding?
Vitalik: I don't think it is necessary in the short term, but it is necessary in the long term. The scalability brought about by using Rollup is limited. Every transaction in Rollup Party 1 will still have some transactions on the Ethereum chain (layer 1). Some applications will perform 100x, 200x or 500x faster. In the short term such performance improvements are sufficient. But in the long run, when more users start to use the blockchain, such as 500 million new users of Ethereum, Rollup is not enough. At this time, we need to combine the two technologies of Rollup and sharding.
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Do you have any expectations in terms of community building in China?
Vitalik: I hope that these expanded technologies of Rollup can get mutual support from community users. Because the ecology of Ethereum will have many challenges, including challenges from scalability, from the complex and complete version of Ethereum 2.0 and the POS process, as well as security challenges and privacy challenges. But we also have more great technologies, and we have great global communities. Therefore, I hope that everyone will support and help each other, so that we can build a better blockchain ecosystem that is available to more people.
Gulu: We also hope that the entire Chinese Ethereum community can remain united as always. Together, drive exciting projects that make it accessible to more people in the world.
The above is the content of the notes of this online AMA, organized by "walking". Statement of interest: The editor of this article, "Walking", holds ETH spot and participated in Ethereum graphics card mining.
