Offchain Labs unveils BOLD protocol for permissionless validation across Arbitrum chains

Offchain Labs, the team behind Arbitrum, has introduced Bounded Liquidity Delay (BOLD), a new dispute protocol aiming to provide decentralized validation of fraud proofs across its Layer 2 blockchains. 

Layer 2 chains on Arbitrum, specifically One and Nova, utilize optimistic rollup technology to synchronize their state with Ethereum. This is done by validators who publish fraud proofs to the Ethereum mainnet. Yet, the current validation process for publishing these proofs is based on a permissioned system.

A permissioned system here means the Arbitrum network's validation process or the submission of fraud proofs on the Arbitrum chains is currently limited to a selected group of approved participants and specific actions require prior authorization.

In a blog post, Offchain Labs suggested said BOLD will be utilized to offer a permissionless security design for Optimistic Rollup chains, while also reducing latency during state settlements between Layer 2 and Ethereum’s mainnet.

Arbitrum plans BOLD testnet

It's worth noting that BOLD is still under development and will require additional testing before its official deployment. 

Offchain Labs has shared a detailed roadmap for BOLD, including plans for launching local devnets and a public testnet. This provides the Ethereum community a chance to engage directly with the protocol, though a specific timeline hasn’t been provided.

Offchain Labs has made the BOLD code and its research specifications publicly available on Github. Addressing security concerns, the code has undergone an audit by Trail of Bits, Offchain Labs said. 

Arbitrum is the most widely used Layer 2 on Ethereum. The total value locked on Arbitrum remains the highest among all Layer 2 solutions, standing at just shy of $2 billion.