Fraud Proofs Are Broken. And a collaborative effort is needed to fix them.

Permissionless interactive fraud proofs for optimistic rollups are vulnerable to Sybil attacks, and the author calls for open, public research collaboration between optimistic rollup teams to address this. Three candidate algorithms are named: Cartesi's Permissionless Refereed Tournaments (PRT), Arbitrum's Bounded Liquidity Delay (BoLD), and OP Stack's Fault Proof System (OPFP), each with issues that undermine safety, settlement speed, or decentralization. For Canetti-based designs made permissionless, settlement delay grows linearly with the number of Sybils, while PRT's delay grows logarithmically but takes about a week per match.