A multi-hop cross-blockchain transaction model based on improved hash-locking

Blockchain is a decentralised, trust-free distributed ledger technology that has been applied in various fields such as finance, supply chain, and asset management. However, the network isolation between blockchains has limited their interoperability in asset exchange and business collaboration since it forms blockchain islands. Cross-blockchain is an important technology aiming to realise the interoperability between blockchains, and has become one of the hottest research topics in this area. This paper proposes a multi-hop cross-blockchain transaction model based on an improved hash-locking consulted by the notary and users. It can solve the security problems in the traditional hash-locking, and prevent malicious participants from creating a large number of transactions to block cross-blockchain system. Moreover, a notary multi-signature scheme is designed to solve the problem of lack of trust in the traditional model. A multi-hop cross-blockchain transaction loop is designed based on the loop detection method of directed graphs. The transaction process of key agreement, asset locking, lock releasing and security analysis based on the model is discussed in detail. Experiments of cross-blockchain transactions are carried out in Ethereum private chain, and prove that the proposed model has good applicability.