A post-quantum blockchain notary scheme for cross-blockchain exchange

Due to its decentralized nature, blockchain serves as a foundational platform for smart trans-portation, enabling peer-to-peer communication. However, exchanging data between different blockchain applications often poses a complex challenge known as cross-blockchain exchange. To address potential vulnerabilities and tackle challenges related to cross-blockchain exchange, we introduce post-quantum techniques that utilize secure blockchain notary schemes. First, we present a multi-signature method employing multivariate cryptographic primitives, offering se-curity in the face of quantum computer attacks. Second, building upon our initial technique, we develop a post-quantum notary scheme to enhance the security of cross-blockchain exchanges. Finally, utilizing the post-quantum notary scheme, we propose a post-quantum cross-blockchain exchange model. We implement this scheme on the blockchain using Python and analyze the experimental results of the cross-blockchain exchange model. The integration of our blockchain design into intelligent transportation systems offers several advantages, including improved security, transparency, and efficiency.