According to Foresight News, Arbitrum has launched the on-chain permissionless verification scheme "Bounded Liquidity Delay" (BOLD) on the testnet to achieve the Stage 2 goal of Rollup security.
Foresight News notes that Vitalik had previously proposed an evaluation framework to help users understand the degree of trust in Rollup centralized participants or transparent codes, dividing Rollup into three levels, namely Stage 0, Stage 1, and Stage 2. The ultimate goal of Rollup security is to reach Stage 2, which means completely getting rid of the "training wheels".
