Cross-Chain Finality Reorgs

Cross-Chain Finality Reorgs refer to situations where a blockchain undergoes a reorganization, invalidating blocks that were previously considered finalized, which can cause significant issues for cross-chain protocols. If a bridge has already processed a transaction based on the initial state, a reorg on the source chain could lead to a state mismatch.

This is particularly dangerous for atomic swaps or cross-chain lending, where assets might be released based on a block that no longer exists in the canonical chain. To mitigate this, protocols often require a higher number of block confirmations before considering a transaction finalized.

This increases latency but is necessary to protect against the inherent probabilistic finality of many proof-of-work and some proof-of-stake chains. Understanding the finality characteristics of different chains is essential for cross-chain architectural safety.