A bridge contract is a smart contract that moves, locks, mints, burns, or otherwise represents assets between blockchains or between network layers. It acts as a trust boundary: users deposit value on one chain, and the bridge arranges an equivalent transfer or representation on another.
Bridge contracts matter because they concentrate risk. If the contract logic, validator set, relayer, or admin keys are weak, attackers can mint unauthorized assets, release locked funds, or bypass message verification. Defenders watch for abnormal mint or burn events, mismatched lock-and-release records, unusual signer activity, and unexpected pauses. Because bridges often secure large amounts of value, a single flaw can force wallets, transfers, or whole networks offline to contain damage.