Why does a valid signature on one chain still authorize a transfer on another?
机会
Cross-chain bridges sign messages to authorize transfers, but most protocols do not include the destination chain ID or action type inside the signed payload itself. An attacker who sees a legitimate signed message can broadcast it to a different chain or replay it as a different action, and the receiving contract cannot distinguish the replay from a fresh authorization. The CrossCurve bridge lost $3M in February 2026 this way, and replay-class bridge incidents have totaled over $180M with a median six-week window from deployment to first exploit. ERC-7281 standardizes cross-chain token interfaces but does not mandate domain-separated signing across the broader message layer. No enforced standard today requires that every signed cross-chain payload carry a chain ID and action-type commitment that makes re-broadcasting structurally invalid.
为什么重要
Domain-separated signing is the missing primitive that makes a signed cross-chain message valid exactly once on exactly one chain.
我如何评估机会
机会评分是我的个人判断，而非量化指标：痛苦程度、发生频率，以及当前解决方案的匮乏程度。分数越高，意味着我认为越值得去构建。
出现时造成的痛苦程度。
人们实际遇到它的频率。
当前针对它的优质工具有多匮乏。