BTR-SDN: A Blockchain-enabled Trusted Routing Scheme for SDN Interdomain

With the evolution of Software-Defined Networking (SDN) toward distribution, cloudification, and servitization, multi-controller architectures have been widely adopted to enhance scalability. However, such architectures face challenges such as degraded inter-domain communication stability and security risks inherent in centralized trust mechanisms. To address these issues, we propose a Blockchain-enabled Trusted Routing scheme for SDN interdomain, called BTR-SDN. First, a multi-dimensional dynamic trust assessment model is designed to characterize and dynamically update the trustworthiness of participating entities by quantifying nodes’ historical behavior, performance metrics, and inter-domain reputation propagation. On this basis, a trust-aware hierarchical topology reconstruction and route pruning mechanism is introduced to adaptively adjust network views and path selection strategies according to trust assessment results, thereby enhancing the reliability of inter-domain communication. Furthermore, by leveraging the immutability of blockchain, critical information such as flow rules and routing decisions is anchored on-chain for attestation, while smart contracts are employed to automate policy enforcement, forming a closed-loop trustworthy assurance system. The experimental results demonstrate that BTR-SDN can not only allocate highly trusted paths suitable for various types of services, improving end-to-end transmission quality, but also effectively identify and isolate malicious nodes, significantly enhancing the security of inter-domain communication.