The technical architecture and details of three cross-chain approaches is described in this standard, including Centralized/Multi-signature Notary-based cross-chain technology, HTLC-based cross-chain technology and Relay Chain-based cross-chain technology.

This standard establishes criteria and requirements for interoperability of blockchain networks and corresponding cross-chain transactions. The stated technical specifications and requirements support universally needed interoperability of blockchains and are applicable to most cross-chain scenarios. The specified consistency requirements apply to all cross-chain transactions under different cross-chain protocols.

This document provides a uniform standard for the interoperability of blockchain networks. It provides a classification of cross-chain protocols, including centralized/multi-signature notary, Hash Time Locked Contract (HTLC), relay chain, etc. It provides requirements relevant to the cross-chain smart contract, cross-chain message format, cross-chain transaction process in different cross-chain protocols and consistency considerations of cross-chain transactions.