Vitalik Buterin unveils plan to solve cross-chain L2 interoperability

Ethereum co-founder Vitalik Buterin has just shared his vision for cross-chain interoperability between Ethereum layer-2 networks, which could vastly smoothen the experience within the Ethereum ecosystem. 

In a post on X on Aug. 6, Buterin responded to a question on the most promising paths to addressing cross-layer-2 interoperability.

The question followed Buterin’s Aug. 5 post stating “I think people will be surprised by how quickly ‘cross-L2 interoperability problems’ stop being problems and we get a smooth user experience across the entire Ethereum-verse.”

He added that he is seeing “lots of energy and will to make this happen,” before highlighting a number of Ethereum Improvement Proposals (EIPs) on the roadmap to cross-L2 compatibility.

One stage on the roadmap is EIP-3370 which introduces a new address standard to be adapted by wallets and dApps to display chain-specific addresses by using a human-readable prefix.

Another step on the upgrade path is EIP-7683 which aims to create a standard way for different Ethereum layer-2 networks to communicate and execute trades across chains.

Currently, it's complex and often inefficient for users to trade assets between different networks so creating a new standard set of rules that all chains can follow would alleviate this issue.

Also on the roadmap is EIP-3668 which is a proposal that outlines a method for Ethereum smart contracts to access off-chain data in a standardized way.

Buterin calls this “layer-2 light clients” as it aims to standardize how Ethereum contracts can use off-chain data. This makes it easier and more efficient for developers to build applications that require large amounts of data without incurring high on-chain storage costs.

He also mentioned “cross-L2-replayable account state updates,” which he explained in a blog post in 2023. This refers to how layer-2s receive recent L1 state updates while maintaining security and low latency.

Buterin mentioned a few phase 2 updates to further improve cross-chain L2 compatibility including keystore rollups, and proof aggregation.

With regards to compatibility with existing zero-knowledge and optimistic rollups, he said that these “stage 1” updates are “completely independent of the details of rollup tech,” before concluding:

“Eventually, I think all rollups will go zk (and existing zk rollups will have to redo their tech stack), in order to finalize to Ethereum once per slot. But that's like 5+ years away.”

Earlier this year, investment manager VanEck predicted that Ethereum L2 scaling networks would hit a $1 trillion market capitalization in six years.