After nearly 5 years of R&D and brewing, the Linea team announced the launch of the mainnet Alpha during the Paris ETHCC conference in July, which aroused widespread concern from the community. As of August 4th, according to Dune data, more than 100 ecological projects have flooded into its main network within a week, with more than 20,000 ETHs entered, more than 170,000 transactions, and more than 100,000 interactive addresses. 127,000, making Linea one of the largest and fastest-growing projects on Goerli.
Since the beginning of this year, the ZK track has entered the stage of an arms race, and this competition has entered a fierce state in recent months. zkSync and Starknet followed the OP camp and rushed to release their own L3 plans. Also at the beginning of the year, Linea squeezed into the already crowded ZK track with a sudden appearance, and gradually attracted more and more users and attention as a dark horse.
In March of this year, the "Web3 giant" ConsenSys launched a public test network and renamed it Linea. This test network, which will be launched in the fourth quarter of 2022, has processed more than 350,000 on-chain transactions in three months. In an official blog post, the team wrote: "Linea represents the next evolution of the ConsenSys zkEVM to power a new generation of dApps on Ethereum."
This blockchain expansion solution built by the owner of MetaMask hopes to combine powerful zero-knowledge proofs with an ecologically active EVM to help developers build or migrate existing dApps in the easiest way. As the Type2 zkEVM equivalent to EVM, Linea provides a new possibility to solve the compatibility problem between ZK Rollup and EVM. In addition, ConsenSys also hopes to make full use of its own ecological advantages, allowing Linea to natively integrate the company's MetaMask wallet and developer toolkit Truffle.
Declan will join the ConsenSys team in 2021 as the Linea product leader. The core responsibility is to think about the functions that the Linea core development team should promote, and to gain insight into the importance behind these functions, as well as the challenges that customers and partners may encounter when using our network . But Declan said in the interview that from a broader perspective, his long-term goal is to gradually make his role "redundant."
“It may sound conceited, but I think the real success for Linea is that people have paid more attention to our Web3 infrastructure and team. When people focus on the application itself, rather than the infrastructure behind it, we know the direction That's right. This mindset is not new in the Web2 world. For example, people usually don't care which cloud server Facebook is running on, what they really care about is the Facebook application itself. So this is what we are building things to do.”
Recently, BlockBeats interviewed Declan Fox, in-depth discussions on Linea mainnet Alpha, ConsenSys ecological layout, the current status and future of the zkEVM track, account abstraction, and Multi Prover (Multi Prover) and other topics.
About Mainnet Alpha
At the ETHCC conference in July, Linea released its mainnet Alpha. Driven by airdrop expectations and a series of mission activities, in less than a month, the TVL on the Linea network has exceeded 30 million US dollars, and more than 100 application projects focusing on DeFi have also rapidly emerged in the ecosystem. However, during the interaction process, there are not a few feedbacks about "difficult to cross-chain" and "slow interaction". In this regard, what explanation will the Linea team give?
According to L2BEATS data, the TVL of Linea’s main network has increased by more than 30 million US dollars in about two weeks, and is currently stable at around 28 million US dollars
BlockBeats: First of all, I would like to congratulate you, the TVL breakthrough of the Linea mainnet has exceeded 30 million US dollars in such a short period of time. In your opinion, what is the main reason?
Declan Fox : I think there are two main reasons for our success. First, as you said, we've built a lot of momentum from the testnet. The Linea testnet has launched a 9-week "Linea Tour", where users can experience dApps with different themes every week, such as DeFi week, NFT week, cross-chain week, etc. This event was very successful, we saw about 50 million transactions, and attracted many new interesting protocols to join, such as the account abstraction protocol, which attracted more than 1 million user operations on the testnet.
We carried the momentum forward with our mainnet launch soon after our testnet event. Secondly, when the mainnet was launched, we also conducted an NFT airdrop, which was one of the largest on-chain NFT airdrops, airdropping 352,000 NFTs to testnet event participants to reward them for helping to test the network, promote The mainnet is online. We have also opened up the public free minting of NFTs to more people.
I think the second reason is that people see the prospect of Linea, they are looking forward to the future of Linea. As a zkEVM public chain, Linea can seamlessly migrate existing dApps or develop new dApps for developers. At the same time, Linea is also integrated with other ConsenSys products, and is integrated into MetaMask by default when the mainnet is launched.
Not only does this make it easier to attract users, it also means for developers that their users can easily access dApps on the Linea mainnet. I think people see the value in this integration and are jumping into the Linea ecosystem even though it's still in its infancy. We've also intentionally marked this as an Alpha release to make it clear that this is a major milestone. There are now more than 30 million TBRs on Linea, not including our upcoming Token Bridge, which can realize the cross-chain of stablecoins and other ERC20 tokens.
Linea has many more exciting features coming, and many dApps are also waiting for these features to go live. All in all, Linea is off to a great start so far.
BlockBeats: You just mentioned many DeFi and NFT applications based on Linea. With the launch of the mainnet Alpha, which type of applications do you most hope to see appear on Linea?
Declan Fox : DeFi is definitely a focus area for Linea. In cryptocurrency and Web3, DeFi already occupies an important position, and Linea brings more possibilities to DeFi.
First of all, Linea is not only a general-purpose smart contract platform that supports the combination and construction of different DeFi protocols on it, but also provides lower gas fees and higher throughput, which is not available in Ethereum. This brings a better experience for DeFi users.
At the same time, as a ZK rollup, Linea inherits the security of Ethereum and does not need to make dangerous trade-offs like sidechains. As a ZKrollup, Linea can complete the certainty of L2 transactions within minutes, which is critical to DeFi, and can provide certainty guarantees for high-value transactions within minutes instead of weeks as it used to.
In addition, considering the cross-chain bridge with other systems such as Ethereum, Linea's fast finality can also greatly improve the efficiency of cross-chain capital use. This is similar to countries that have lifted capital controls and can attract external funds more smoothly.
To sum up, as a zkEVM rollup, Linea brings unique advantages to DeFi, which not only guarantees security, but also provides an efficient and low-cost user experience. This will be the key to the flourishing of DeFi on Linea.
Blockbeats: Next I would like to ask about the delayed withdrawal time. Linea previously announced that for security reasons, it will artificially set a withdrawal delay of at least 8 hours. Can you explain the reasoning behind this move?
Declan Fox : The 8-hour withdrawal delay can be seen as a temporary safety measure or "training wheel". As I said, the Linea mainnet is still in the Alpha stage, we have just deployed the system, and we need to ensure that users' assets are well protected when the system is still relatively early.
The purpose of the 8 hour withdrawal delay is to give enough time to pause operations or intervene if there is any issue with the rollup or if we need to investigate to protect user assets. We mentioned in the risk disclosure document that a safety committee could be activated to take action and intervene if necessary. We do not wish to do this, but it is a security measure.
The current withdrawal delay is 8 hours, and we will gradually remove this limit as we learn more about the system and the mainnet runs longer and everything works. I believe zkSync still has a withdrawal delay of 21 hours now, maybe even longer. But all of these systems start out with "training wheels," and I believe that over time, these limitations will continue to decrease.
BlockBeats: However, in the interaction with the Linea network, you do hear complaints about network delays. What is the reason for this?
Declan Fox : There are two types of delays. The certainty on Layer 2 is softer, while Layer 1 is the finality of transactions confirmed by Ethereum itself. The current delay in Layer 1 is mainly caused by the 8-hour withdrawal delay we set, but this will gradually decrease over time.
Currently, the delayed block time of Linea itself is 12 seconds, and the quota is 30 million gas. Over the next few months, we will gradually reduce the block time. Reduce latency. Technically there is no bottleneck, we just want to roll out the system incrementally in stages. In the next stage, the block time will be shortened by about 60%, so that it can reach a block time of 4 seconds, and the quota will be reduced to 15 million gas. After that, the block time will be further shortened and the quota will be increased.
It's not easy to reduce latency and increase throughput, but we are in a good position because we have the Basu team supporting us technically. The Basu team has currently executed blocks on Layer 1 of Ethereum, and will become Linea's ordering node in the future.
This is an experienced team who have developed battle-tested client software that works seamlessly on Linea. This will be a key differentiator in ensuring that we can both produce blocks quickly and accommodate a high volume of transactions. In short, this is not limited by technical bottlenecks, but the result of the gradual rollout of the system in stages.
About Linea and ConsenSys
I have to admit that many people pay attention to Linea because of the strength behind it - "Web3 giant" ConsenSys. Founded in 2014, the OG encryption company has now spread across the entire encryption industry. As one of the largest and most fundamental entities in the blockchain technology space, ConsenSys employs top computer scientists, protocol engineers, software developers, and enterprise delivery experts. In 2018, ConsenSys was called "the Ethereum community's most famous and pervasive developer and promoter of decentralized applications" by The New Yorker.
Among the many products it has created, MetaMask is undoubtedly the most influential. Now, this Web3 wallet with a huge user base will bring Linea a natural advantage in the number of users. So far, Linea has raised US$726 million in multiple rounds of financing, with a valuation of about US$7 billion. As a strong player of ConsenSys, Linea will undoubtedly create a world for ConsenSys in the expansion track with the most market space. Of course, this also leads to worries and thinking about the decentralized spirit of Web3 and the centralized development of large teams.
ConsenSys founder and CEO Joe Lubin speaking at Ethereum New York 2019 with the background title "The Age of Collective Capitalism"
BlockBeats: In your opinion, what role does Linea play in the ConsenSys ecosystem?
Declan Fox: ConsenSys has a complete set of products. ConsenSys has existed since the beginning of Ethereum, and its founder Joseph Lubin is also the co-founder of Ethereum. It can be said that Ethereum is the blood of ConsenSys. ConsenSys has supported Ethereum throughout its development, launching Infura, which manages more than half of Web3 traffic, and incubating MetaMask, the leading Web3 wallet.
ConsenSys has also incubated many public products, such as Baesu (one of Ethereum's leading execution clients), Teku (one of ConsenSys's Ethereum 2.0 merged important execution clients), Web3Signer (used to securely sign private keys or transactions) tools), etc. Linea serves as a key infrastructure to expand the transaction capabilities of Ethereum. We realized this need a few years ago, and also needed to maintain the network effect of the EVM as it scaled.
Therefore, Linea can be said to have perfected the ConsenSys technology stack, so as to influence and provide support for the entire process from users initiating transactions through MetaMask to the RPC layer, and actually executing transactions on a scalable general platform, and this general platform is EVM compatible. The Linea. It can be said that Linea is perfectly integrated into the solution portfolio provided by ConsenSys to help promote the development of the entire ecosystem.
BlockBeats: But it has also raised concerns among some that ConsenSys is becoming a centralized force in the Web3 and crypto world. The wallet most people use is MetaMask, and ConsenSys provides RPC for it, and more people will use the Linea network soon. I wonder what the Linea team thinks about this view?
Declan Fox : I think we should see that all of these products have plans to move towards decentralization and permission-free innovation.
Looking at them one by one, first of all, Linea has released a roadmap for decentralization and trust minimization when the main network was launched, which clarifies that Linea's operations and governance will be gradually decentralized and reduce its dependence on ConsenSys. MetaMask users can also choose a different RPC node and use a non-Linea network. The team is developing MetaMask Snaps, allowing any developer to extend MetaMask without permission.
Linea also supports using any wallet. It can be seen that ConsenSys has boosted the development of the entire Web3 ecosystem by providing these key infrastructure products. However, the core concepts of these products still adhere to the principles of decentralization and user freedom of choice. Users can choose to quit at any time according to their own needs.
BlockBeats: Let's talk about account abstraction on Linea. As a L2 network that natively integrates MetaMask, can Linea better assist MetaMask to achieve innovation in account abstraction?
Declan Fox : Yes, our philosophy is permissionless innovation. So even for Linea today, there are other wallets that support Linea. Likewise, MetaMask will continue to support all other networks except Linea. We're trying to find ways to collectively improve the user experience, but there's a delicate balance between maintaining permissionless innovation while fostering an environment that solves user problems and moves the space forward.
It is not realistic to implement account abstraction at the protocol layer in the short term. Although it is on the roadmap of Ethereum, we will not see the landing of EIP-4337 tomorrow. We currently implement EIP-4337 and smart contract accounts at the application level, but it is still costly and more suitable for application on Layer 2. As a Layer 2 zkEVM public chain, Linea is fully compatible with the Ethereum mainnet.
Therefore, various standards promoted by the Ethereum community, such as 4337, can be easily implemented on Linea. This allows us to leverage the account abstraction of the fast-growing community, supporting this functionality from day one in the Linea ecosystem. In addition, we will also look to support new endpoints to simplify management and protect the RPC layer and serialization layer from denial of service attacks. These all stem from the larger community consensus of Ethereum. Since Linea is a fully compatible zkEVM, we are lucky to easily join and continue the network effect of Ethereum.
About zkEVM and RaaS
When talking about Linea, the topic of zkEVM cannot be avoided. As the "hottest" track in the encryption industry, the zkEVM field brings together the most capable and intelligent developers in the industry. In addition to the different types of technical implementations of ZK L2, "RaaS" has recently become the "hardest hit area" for this group of geniuses. After the OP camp launched OP Stack and Orbit successively, zkSync and Starknet followed suit and released ZK Stack and Appchain. As one of the powerful representatives of zkEVM, will Linea do the same in this field?
"Rollup SDK Landscape" sorted out by Kayla Phillips, partner of Truffle Ventures
BlockBeats: Next I want to talk about zkEVM in general. Why did Linea choose to do Type2 zkEVM? Compared with Polygon zkEVM and Scroll, what is the biggest advantage of Linea?
Declan Fox : Our decision to build the Type2 zkEVM dates back to 4 years ago, in January 2019. At the time, our R&D team, Consensus R&D (which also helped implement the merge and engine APIs) was working on scaling solutions. In 2019, many discussions focused on optimistic rollup, and zero-knowledge technology is still in its infancy, and EVM is not good for direct circuit simulation.
So many people don't want to go the route of zero-knowledge proof, but build their own zkEVM, these virtual machines have their own programming language, and EVM has the largest ecosystem of developers, tools and dApps in Web3. Considering the huge EVM ecology, we don't want to start from scratch, but maintain the network effect of EVM. So at that time, we believed that zero-knowledge proof is the best expansion solution in the future, and at the same time, the network effect of EVM should be maintained. So we set out to achieve this goal, and after 4 years, we finally achieved a zkEVM that is both high-performance and EVM-compatible.
Being Type2 means that we are largely equivalent to the EVM, we use the same Solidity compiler as Ethereum, and the RPC interface is also compatible with Ethereum JSON-RPC. This is very friendly to developers, they do not need to learn new languages, new tools, and existing dApps can also be seamlessly connected. This is also good for decentralization, users can opt out at any time and there is no risk of vendor lock-in. We follow the standards of Ethereum, which is consistent with any project that implements EVM, which is also good for decentralization.
There are other projects that are building similar Type2 zkEVM. I think the difference between Linea and other projects is mainly in two aspects, one is technical implementation, and the other is ecological integration.
In terms of technology, we can bring higher performance. Specifically, the speed and verification cost of Prover in zero-knowledge proofs are critical to user experience and transaction fees. We have been building our own Prover since January 2019. After 4 years and a lot of R&D resources, it can be said to be the best in the industry. We directly arithmeticize the EVM operation instead of adding an intermediate translation step. This allows us to make optimal adjustments at a lower level, which is not possible with other systems.
In terms of ecological integration, Linea has been deeply integrated with other products of ConsenSys. For example, the native integration with MetaMask is just the beginning, but it has shown the possibility that we can provide a complete user experience from the wallet to the RPC to the execution level. In addition, Infura provides infrastructure support, which can improve the stability and security of Linea. Finally, the Basu team provides us with execution clients and orderers. This collaboration creates a more holistic and coherent user experience that is unmatched by other platforms.
Related reading: "Interview with Polygon zkEVM: MATIC One Token is Enough"
BlockBeats: In addition to different types of ZK Rollup, another popular concept recently is "RaaS" (Rollup as a Service). As a strong competitor in the zkEVM field, does Linea have any plans in this direction?
Declan Fox : It's an interesting topic indeed. What we're talking about in general is the proliferation of Appchains or use-case-specific chains, which isn't really a new concept. I think that with the emergence of rollup, starting a new chain has become very simple and more meaningful than the Appchain that was monolithic in the past.
The reason why someone wants to do this is sometimes because they need a more flexible execution environment, or they may want to have their own isolated block space and have complete control over the throughput and needs of the application. I think it is unlikely that there will be only one shared execution environment to handle all transactions in the future. This is similar to the development of computing, from the initial single server running multiple applications to the later trend of one application corresponding to one server.
Of course, there is still value in a shared execution environment, and we can continue to advance its development and see what use cases we can build. The shared execution environment can achieve synchronous composition, which is difficult to replicate in the fragmented multi-chain world. Linea has committed to open source code, so Linea's technology stack can be instantiated. If the trend of fragmentation continues to intensify and there is more demand for different instantiations of the Linea virtual machine, then extremely fast proof generation will be critical in order to perform state verification with other chains and ensure smooth user experience.
Linea happens to have a very fast Prover, so if this trend continues, Linea's technology stack and virtual machine will be very attractive to teams looking to build their own execution environment and eventually aggregate to the Ethereum mainnet. Many teams are aware of this in initial discussions, but we haven't heard anything official yet.
About Multi Prover and the Future
In the Linea team, there is another focus, that is, Multi Prover. What does this concept refer to? What can multi-provers bring to zkEVM and the crypto industry? Why did the team feel it was so important?
BlockBeats: Linea has been promoting the concept of "multiple provers". What is the team's current thinking on this proof generation model?
Declan Fox : Yes, this is what was mentioned in the decentralization and trust-minimization roadmap that we released when the mainnet Alpha launched. The basic idea is that a Layer 2 transaction or batch of transactions can be simultaneously proved by multiple zero-knowledge proofs. As long as the majority of them are verified on Layer 1, security is guaranteed. This is more reliable than a rollup with only a single prover, without the risk of a single point of failure. As Ethereum continues to evolve and specifications need to be re-audited and updated, the multi-prover model can help get rid of various limitations.
As a zkEVM that closely replicates the EVM specification, Linea is in an excellent position to unlock the multi-prover pattern. I think once this is achieved, it will attract new risk-averse businesses, liquidity and users to Layer 2. Because it gives them better assurance that even if a certain prover is vulnerable, the system will still remain secure. This is similar to having multiple execution clients on the Ethereum mainnet, providing diversity. We hope to replicate the same level of security at Layer 2.
BlockBeats: Does the team currently have a mature design plan?
Declan Fox : The specific design scheme of multi-prover is still an open topic, and we don't want to prematurely converge to a fixed scheme. But basically, there will be three different implementations of zkEVM generating proofs for a batch of transactions at the same time. As long as a quorum is reached on the Layer 1 verification contract, for example, two out of three implementations are valid, then even if one implementation has a problem, security can be guaranteed.
Multiple provers also allow us to innovate more in Prover because there is a fallback guarantee. In short, multiple provers bring many interesting possibilities, which is also a long-term goal in our roadmap. We will keep an open mind about the specific technical solutions, but we will not fix them prematurely. Our goal is to achieve similar security diversity at Layer 2 as the Ethereum mainnet. Multi-provers not only improve stability, but also give us more room for innovation in proof generation, which is very exciting. It will still take time to implement multi-provers, but it is definitely our long-term goal and vision.
BlockBeats: Are there discussions within the team about interesting things that can be done with the multi-prover model?
Declan Fox : From a user perspective, the multi-prover pattern is roughly the same as it is today. But it can give developers and users greater confidence in the maturity of the system due to increased diversity and resilience to errors. This is similar to having various execution clients and consensus clients on the Ethereum mainnet. If one of the clients makes a mistake, Ethereum is still safe as long as the overall implementation achieves enough diversity. We are applying these design principles of Ethereum to Linea and Layer 2.
BlockBeats: Overall, what do you think is the most important next step for the team?
Declan Fox : What we are most concerned about is the growth of user adoption, so we plan to start from several aspects.
First, continue to reduce transaction costs. Linea’s fees are already much lower than Ethereum’s, but there is still room for further declines in the short term. We can use the way of aggregation proof, we use zero-knowledge proof or validity proof to complete the second layer transaction on Ethereum. In fact, we can aggregate many proofs together and prove them recursively in order to amortize the fixed proof verification cost over a larger set of transactions, reducing gas costs.
Data compression can also help reduce the cost of calling data from Linea to Ethereum. We also hope that with the implementation of EIP-4844, the cost of publishing call data to Ethereum will also be reduced. This Ethereum protocol change will be applied later this year, at which point we will pass the cost savings on to users.
The second is to improve the onboarding experience for new users. Simplify the process of opening a wallet and using DApp for the first time through account abstraction to attract a new wave of users to join. We have implemented the application of EIP-4337 to account abstraction on Linea. On the Linea mainnet, we are also working with partners such as Pimnico to explore the possibility of opening a wallet without entering a password.
In addition, security must be strengthened. We will encourage ecological partners and security-focused protocols to provide insights and information about malicious smart contracts to users, helping users avoid being cheated in a non-permissioned manner. There is currently a lot of fraud on the chains, which is not conducive to mass user adoption. We will strive to improve security in a decentralized manner while maintaining openness.