Vitalik: Layer2 Design Similar to Sharding in Ethereum, with Many Aspects Done Better
In a recent post, Vitalik Buterin, the co-founder of Ethereum, stated that the existing Layer2-centric design is actually very similar to the Ethereum sharding approach that was previously pursued. However, he believes that many aspects can be improved, such as allowing more autonomy for Layer2 developers and providing the ecosystem with more innovation and flexibility.
Vitalik’s remarks suggest a shift in his preference towards Layer2 solutions. He points out that Layer2 and sharding are often described as two strategies for blockchain scalability, but in reality, the underlying technologies for scaling are the same.
Layer2-centric design is similar to sharding in that users have some form of data sharding, which can be thought of as having fraud proofs or zero-knowledge proofs. Users interact between different shards, corresponding to interactions between different rollups.
The main difference between Layer2 and sharding lies in the level of autonomy and flexibility given to different chains and shards, and how much room is available for developers to innovate.
In terms of execution environment diversity, Ethereum had previously attempted to improve sharding in 2019 by allowing different shard areas to adopt completely different virtual machines and account models. However, this proved difficult to implement and was ultimately abandoned. Layer2, on the other hand, can easily achieve more flexibility and innovation in the execution environment.
Vitalik states that Ethereum Layer2, including rollups, valdium, and Plasmas, currently serves as the execution environment for the ecosystem. While the Ethereum community typically focuses on L2 with an equivalent EVM (Ethereum Virtual Machine), there are actually more diverse and innovative Layer2 solutions being developed, such as Arbitrum Stylus, Fuel, and Aztec.
Compared to attempting to create a super virtual machine that covers all possible designs, these specialized platforms are expected to be more efficient.
When it comes to the trade-off between speed and security, sharding can provide higher security for users, and the current transaction fees on the Ethereum mainnet are competitive, costing less than a dollar. However, not all applications require the same level of security. For example, social media or gaming applications may find even a $0.01 transaction fee too high.
Different applications have different security requirements, and Layer2-centric design can accommodate this by providing corresponding environments based on different needs.
Another security-related trade-off is cross-rollup transactions. Currently, the Ethereum ecosystem has optimistic rollups, ZK rollups, and various combinations of proof-of-time windows. However, optimistic rollups require complex fraud proof logic to be managed on-chain, and assets need to undergo a one-week withdrawal challenge. This compromises the efficiency of cross-rollup transactions.
However, Vitalik believes that within the next 5 to 10 years, all rollups will be ZK rollups, and with highly efficient proof systems like Binius and Circle STARKs, along with the maturity of proof aggregation layer techniques, cross-rollup transactions in Layer2 will not be a problem.
In terms of transaction speed, Ethereum produces one block every 12 seconds, and the average user submitting a transaction needs to wait about 6 to 7 seconds to be included in a block. Vitalik believes that this is comparable to the waiting time when using a credit card for payment.
However, many applications require higher speed, and Layer2 can meet this requirement. Many Layer2 solutions are already exploring block times in the range of hundreds of milliseconds. For example, Layer2 can provide higher speed through preconfirmation, where validators sign the transaction after it is submitted, declaring that it will be included at a specific time. If the transaction is not included, the validator will be penalized, achieving more efficient soft verification.
Of course, these designs can also be implemented on Layer1, combining different shards with different security levels. However, this would increase the complexity of the protocol and may introduce risks of consensus overload. By providing these trade-offs through Layer2, Ethereum can essentially avoid these risks.
Vitalik believes that a Rollups-centric design can bring better scalability to Ethereum compared to sharding based on specific political positions within the Ethereum ecosystem.
In addition to technical comparisons, Vitalik believes that Layer2 also creates an incentive space that encourages developers to build and maintain Layer2 solutions and community support for Layer2.
Each Layer2 is independent, allowing developers to deploy new methods without permission and without the need to convince all core developers that the new methods are safe for the rest of the chain. New features can also be added freely to Layer2. Anyone can explore completely strange ideas, even if they are completely ignored by Ethereum core developers.
If a developer’s Layer2 attempt with new methods fails, it is the responsibility of the developer and has limited impact. In contrast, the functionalities and pre-compiled designs of Layer1 are not the same. Any new update or method that affects the network needs to be comprehensively evaluated, as there may be unexpected consequences and impacts.
Therefore, many Ethereum Improvement Proposals (EIPs) often depend on political factors to determine whether they succeed or fail, to a greater extent than Vitalik would like, regardless of what can theoretically be constructed.
In conclusion, the unique incentive measures generated by the Layer1-centric ecosystem and the Layer2-centric ecosystem will greatly affect the content, quality, and order of construction.
Compared to sharding, which is based on a specific political stance within the Ethereum ecosystem, Layer2 can provide developers with more autonomy and innovation, even without being included in EIPs by Ethereum core developers.
Vitalik believes that a Layer2-centric ecosystem is the true technical form of sharding. In this form of sharding, users can create their own networks with their own rules, which is extremely powerful for ecosystem development and can stimulate a large amount of innovation.
Vitalik is beginning to believe in the potential of a Rollups-centric design for Ethereum.
(Ethereum, Layer2, Rollups, Vitalik, sharding)