How Layer 2 and Execution Sharding Differ by Vitalik

PANews reported on May 23 that Ethereum co-founder Vitalik Buterin published an article titled "How Are Layer 2 and Execution Sharding Different?" The article concludes that "Layer 2" and "sharding" are often described in public discussions as two completely opposite strategies for scaling blockchains. However, when you delve into the underlying technology, you find a confusing issue: the underlying methods used for scaling are exactly the same. These methods include some form of data sharding, fraud proofs or ZK-SNARK proofs, and solutions for cross-{rollup, sharding} communication. The real difference lies in who is responsible for building and updating these parts and how much autonomy they have.

The Layer 2-centric ecosystem is technically a form of sharding, but it allows for the creation of its own shards according to its own rules. This is powerful and fosters a lot of creativity and independent innovation. However, it also faces some key challenges, particularly in terms of coordination. For a Layer 2-centric ecosystem like Ethereum to succeed, it needs to understand these challenges and address them directly to gain as many of the advantages of a Layer 1-centric ecosystem as possible and come as close as possible to the best of both worlds.

It is worth mentioning that Vitalik pointed out the challenges faced by Ethereum's Layer 2-centric ecosystem, including: 1. Transferring tokens from one Layer 2 to another often requires centralized bridging platforms, which are complex for ordinary users; 2. Cross-chain smart contract wallet support is not good; 3. Cross-chain smart contract wallet support is not good. Efforts are being made to improve these three aspects. For cross-chain token swaps, the ERC-7683 standard is an emerging option that, unlike existing "centralized bridges," does not have a fixed central operator, token, or governance mechanism. For cross-chain accounts, most wallets adopt the approach of using cross-chain replayable messages to update keys in the short term and key vault aggregation in the long term. Light clients for L2 are beginning to emerge, such as Starknet's Beerus. Additionally, many more fundamental issues have been resolved through the latest improvements in user experience with next-generation wallets, such as eliminating the need for users to manually switch to the correct network to access dapps.