With the rapid emergence of Internet of Things (IoT) technology, cross-domain collaboration and information sharing among IoT devices have become increasingly critical. However, the security and privacy risks associated with cross-domain communication have also escalated. Establishing efficient and secure authentication mechanisms for cross-domain collaboration among IoT devices remains a complex challenge, particularly in the context of bandwidth-constrained wide-area networks. Most recent cross-domain authentication solutions rely heavily on emerging blockchain technology. However, in bandwidth-constrained scenarios, they may suffer from efficiency losses. Consequently, an effective resolution of cross-domain authentication issues in bandwidth-limited conditions has become a pressing concern. In this article, we introduce an efficient blockchain-assisted cross-domain authentication mechanism, named EBCA, designed for bandwidth-constrained wide area IoT networks. To enhance authentication efficiency, we design a highly efficient multiblockchain architecture, which optimally leverages the underlying network bandwidth, significantly improving throughput and reducing latency for cross-domain authentication. Additionally, threshold signatures are incorporated to minimize communication overhead, further enhancing authentication efficiency. Extensive experiments have been conducted to demonstrate the efficiency of our approach. Our scheme has been shown to increase throughput by approximately 34% when compared to existing methods.
