Arbitrum Launches Bold, Achieving True Permissionless Fraud Proofs
Offchain Labs has activated BoLD (Bounded Liquidity Delay) on Arbitrum One, making it the first major rollup with fully permissionless challenge mechanisms.
Arbitrum One has activated BoLD (Bounded Liquidity Delay), becoming the first major optimistic rollup to achieve fully permissionless fraud proofs. Previously, only whitelisted validators could challenge invalid state roots — now anyone can participate in the dispute resolution process.
The upgrade addresses one of the most common criticisms of optimistic rollups: that their security relies on a trusted set of validators. With BoLD, any participant can stake and challenge a fraudulent assertion, with a guaranteed resolution within a bounded time window.
Offchain Labs CEO Steven Goldfeder described the launch as "the end of training wheels for optimistic rollups," noting that Arbitrum One now meets the criteria for a Stage 2 rollup under L2Beat's classification framework.
The move puts pressure on competing L2s to achieve similar milestones. Optimism's fault proof system, while live, still operates with a security council override. ZK rollups like zkSync and Starknet have their own path to full decentralization through proof verification.
Arbitrum One currently leads all L2s in total value locked at $18 billion, though Base has surpassed it in daily active users.
