Cross-chain bridge

A protocol that transfers assets or value between different blockchains. Common designs include lock-and-mint, where an asset is locked on the source chain and a wrapped equivalent is minted on the destination chain, with the reverse process typically burning the wrapped token and releasing the original; burn-and-mint, where an asset is burned on one chain and minted natively on another; and liquidity networks, which pay users from pools already held on the destination chain.

The two legs appear on separate ledgers. They can often be matched using transfer or message identifiers recorded in bridge events; where these are unavailable, amounts, timing and destination addresses can help establish a probable link. The destination address need not match the source address, and in liquidity networks no mint event occurs on the destination chain. Many bridges rely on validators or multisignature arrangements to authorise transfers, creating potential points of control, compromise or intervention. Investigators should therefore examine both the cross-chain transfer records and the entities or keys controlling the bridge.