PQ-BCDA: A post-quantum blockchain based cross-domain authentication scheme for Internet of Things

The growing deployment of Internet of Things (IoT) devices across heterogeneous trust domains raises critical concerns for secure and efficient cross-domain authentication, especially under the emerging threat of quantum computing. Existing approaches often rely on centralized authorities or classical cryptographic primitives, making them vulnerable to single points of failure and future cryptanalytic advances. To address these challenges, this paper proposes PQ-BCDA, a novel post-quantum cross-domain authentication scheme that combines the Extended Merkle Signature Scheme (XMSS) with a consortium blockchain framework. Our scheme introduces an automated signature lifecycle management mechanism via smart contracts, enabling decentralized trust management and secure authentication without relying on centralized anchors. We formalize a tailored security model based on established frameworks and provide a detailed proof in the random oracle model, ensuring session key secrecy, mutual authentication, and resistance to common attacks. Experimental evaluations on real hardware platforms, demonstrate that PQ-BCDA reduces computational and storage costs by 46% and 33%, respectively.