7. Interchain Services
A cross-chain mechanism is the interoperability between two or more relatively independent blockchains, and it enables the swap and transfer of data, asset and information. On the BSN, every blockchain maintains its own transactions, consensus, and ledgers, carrying business data and information of different DApps. The cross-chain mechanism realizes data sharing and business collaboration among blockchains, and to break the silos between chains, allows data to flow securely and reliably across multiple chains. The main functions of the cross-chain system include: cross-chain registration management mechanism, cross-chain contract functions, cross-chain transaction verification, cross-chain message routing protocol, cross-chain transaction atomicity guarantee, etc.
The BSN Interchain Communications Hub (ICH) adopts the cross-chain protocol of heterogeneous chains and the design of double-layer structure, using relay chains as cross-chain coordinators, multiple heterogeneous chains as cross-chain transaction executors, and acts as a relayer of cross-chain data. By solving validity, security, and transactional issues of cross-chain data, a secure, easy-to-use and efficient cross-chain system is implemented：
Supports both isomorphic and heterogeneous chains.
Supports any information to cross the chains.
Very easy to access. Application chains do not need to do custom development adaptation, just deploy one smart contract per chain.
Transactional support, supporting not only scenarios with the need for ultimate consistency of transactions, but also scenarios with the need for strong consistency of transactions, with support for any transaction, and scalable to any number of chains.
Cross-chain protocols are secure and reliable, based on cryptography and consensus algorithms, and each application chain can verify the legitimacy of cross-chain transactions on its own, thus ensuring the security of cross-chain interactions.
The BSN development team is building the “Interchain Communications Hub” (ICH). A demo version of ICH is now live on the BSN Testnet, integrating two interchain solutions based on the relay chain mechanism: (1) Poly Enterprise developed by Onchain and (2) IRITA developed by Bianjie AI. We welcome developers to try it out and provide feedback and suggestions. We will continue to improve the functionality and expect to release a commercial version in early 2021.