Blockchain Transmission Protocol (BTP)

The Blockchain Transmission Protocol (BTP) is an interoperability protocol developed by the ICON project to send messages, and through them tokens and data, between separate blockchains. In its design, smart contracts on each connected chain act as message centres, and off-chain relays carry messages and block header proofs from one chain to another, where they are verified before being acted on. The aim is to let chains communicate without relying on a single trusted custodian, a weakness of many crypto bridges. BTP sits in the wider field of blockchain interoperability and cross-chain protocols, and the ICON community has built later messaging tools on its ideas. As with other bridges, its security depends on correct verification and code quality. Also see Block Header.