Sequencer-Committee Interaction

When the Arbitrum sequencer initiates posting a data batch through the Committee, it simultaneously dispatches the data, along with an expiration time, to all Committee members via RPC. Each Committee member receives the data, stores it, signs the (hash, expiration time) pair using its BLS key, and returns the signature along with a success indicator to the sequencer.

Upon collecting sufficient signatures, the Sequencer aggregates them to form a valid DACert for the (hash, expiration time) pair. This DACert is then transmitted to the L1 inbox contract, rendering it accessible to the AnyTrust chain software at L2.

In instances where the Sequencer fails to gather enough signatures within the specified timeframe, it adopts a "fall back to rollup" strategy by directly posting the full data to the L1 chain. The L2 software is proficient in understanding both data posting formats (via DACert or full data) and handles each format accordingly.

In essence, AnyTrust, a pioneering innovation within the Offchain Labs ecosystem, signifies a significant leap forward in addressing challenges related to data availability, security, and cost efficiency in blockchain infrastructure. By employing a prudent trust assumption and introducing a fresh approach to data posting, AnyTrust lays the groundwork for more scalable, accessible, and secure blockchain solutions.