A bridge is a protocol or service that lets users move crypto assets from one blockchain to another. Because blockchains do not share state natively, a bridge usually locks, burns, or escrow-holds tokens on the source chain and mints or releases an equivalent asset on the destination chain. Bridges are important because they expand liquidity and let applications work across multiple networks, but they also add trust, code, and operational risk.
In cyber security, bridges matter because attackers and launderers can use them to break the visual continuity of funds. Moving assets through a bridge may create new wallet addresses, new token forms, or activity on a less-monitored chain, making tracing harder. Defenders look for bridge hops, rapid cross-chain splits, and repeated counterparties to cluster related wallets and support freeze requests. Bridges are also a common target for exploitation, since a flaw in bridge logic or key management can expose large amounts of value at once.