A system that locks an asset on one chain and issues a representation of it on another, releasing the original when the representation is destroyed.
Why it matters
A bridge concentrates pooled collateral behind privileged logic that decides when to release it — which is why bridges account for several of the largest losses on record. Four bridge incidents in this tracker failed through key management or authorisation, not cryptography. See how bridges work and why they keep getting exploited.
What you can check
A bridge is only as trustworthy as whatever authorises releases on the destination chain. Published documentation should say who or what signs, how many signatures are required, and whether that set can be changed — and by whom. Validator sets and their thresholds are usually readable on-chain.
Where it showed up
Records in the Incident Tracker that turn on this: Ronin bridge validator key compromise, Nomad bridge replay exploit and Harmony Horizon bridge compromise.
Not advice. Definitions are for understanding, not instruction. Nothing here is financial, legal, tax or security advice.