A Post-Quantum Cross-Domain Authentication Scheme Based on Multi-Chain Architecture

Due to the rapid advancements in network technology, blockchain is being employed for distributed data storage. In the Internet of Things (IoT) scenario, different participants manage multiple blockchains located in different trust domains, which has resulted in the extensive development of cross-domain authentication techniques. However, the emergence of many attackers equipped with quantum computers has the potential to launch quantum computing attacks against cross-domain authentication schemes based on traditional cryptography, posing a significant security threat. In response to the aforementioned challenges, our paper demonstrates a post-quantum cross-domain identity authentication scheme to negotiate the session key used in the cross-chain asset exchange process. Firstly, our paper designs the hiding and recovery process of user identity index based on lattice cryptography and introduces the identity-based signature from lattice to construct a post-quantum cross-domain authentication scheme. Secondly, our paper utilizes the hashed time-locked contract to achieves the cross-chain asset exchange of blockchain nodes in different trust domains. Furthermore, the security analysis reduces the security of the identity index and signature to Learning With Errors (LWE) and Short Integer Solution (SIS) assumption, respectively, indicating that our scheme has post-quantum security. Last but not least, through comparison analysis, we display that our scheme is efficient compared with the cross-domain authentication scheme based on traditional cryptography.