Cross-chain bridge

A cross-chain bridge connects otherwise separate blockchains so assets or data can move between them. A common design is lock-and-mint: the bridge locks your tokens in a contract on the source chain and mints an equivalent wrapped representation on the destination chain. Redeeming reverses the process, burning the wrapped token and releasing the original. Other designs use liquidity pools on both sides or trusted validator sets.

Why it matters

Bridges are essential plumbing for a multi-chain ecosystem, but they concentrate large amounts of locked value in complex contracts and validator systems, making them a leading target for attackers. Some of the largest thefts in the industry have been bridge exploits, caused by smart-contract bugs, compromised validator keys, or flawed message verification. Users should understand that holding a wrapped asset also means trusting the bridge that issued it. Because a bridge must be secure on both chains at once and correctly relay messages between them, its attack surface is larger than that of a single contract, and moving smaller amounts or using well-established, audited bridges reduces exposure.

Common misunderstanding

A wrapped token is often treated as identical to the native asset it represents. Its value actually depends on the bridge remaining solvent and secure; if the bridge is drained, the wrapped token can lose its backing and its peg. Bridging is not a simple, risk-free transfer, and the wrapped asset is a claim on the bridge rather than the native coin it represents.

Related terms

See blockchain, stablecoin, validator and DeFi.