Bridge
A protocol that moves tokens or data between two separate blockchains that cannot otherwise talk to each other.
Blockchains don't natively talk. A bridge fills the gap, moving assets from one chain to another, say Ethereum to Arbitrum. Most lock tokens on the source chain and mint a wrapped version on the destination.
Bridges are among the most dangerous places in crypto. They hold large pools of locked assets, which draws attackers. The Ronin bridge lost about $625 million in 2022; Wormhole lost roughly $325 million the same year.
Before using one, check the audits, how funds are custodied, and who holds the keys. Native bridges are generally safer than third-party ones.
Related terms
Describes activity that spans two or more separate blockchains, such as moving assets or messages between them.
InteroperabilityThe ability of different blockchains to exchange data and value without relying on a central intermediary.
Wrapped TokenA token that represents another asset one-to-one on a different chain, letting it move where it natively cannot.
SidechainAn independent blockchain that runs alongside a main chain and connects to it through a two-way bridge.