New ERC: Crosschain Broadcaster
Abstract
This ERC defines a standardized protocol for cross-rollup message broadcasting and reception via storage proofs. Users can broadcast messages on a source chain, which can then be read by many other chains, as long as those chains share a common ancestor chain with the source chain. This smart contract standard enables trustless message passing across rollups hosted on different rollup architecture stacks.
Motivation
The Ethereum ecosystem is experiencing a rapid growth in the number of rollup chains. As the number of chains grows, the experience becomes more fragmented for users, creating a need for trustless “interop” between rollup chains. These rollup chains, hosted on different rollup stacks, have heterogenous properties, and as yet there does not exist a simple, trustless, unified mechanism for sending messages between these diverse chains.
Many classes of applications could benefit from a unified system for broadcasting messages across chains. Some examples include intent-based protocols, governance of multichain apps, multichain oracles and more.
Specification
Check out the full specification on Github: Add ERC: Crosschain Broadcaster by yahgwai · Pull Request #897 · ethereum/ERCs · GitHub
A work-in-progress reference implementation is also available here; if there is sufficient interest from the community, a full implementation can be built out: broadcast-erc/contracts/reference-impl at main · OffchainLabs/broadcast-erc · GitHub
Please participate in the discussion here to help us evaluate and iterate the Crosschain Broadcaster!
More Resources
Introducing the Crosschain Broadcaster - blog post with high level overview of the standard
FAQs for the Crosschain Broadcaster - common questions from the community thus far