BTR-SDN: A Blockchain-Enabled Trusted Routing Scheme for SDN Interdomain
With the evolution of Software-Defined Networking (SDN) toward distribution and servitization, multi-controller architectures have been widely adopted to enhance scalability. However, such architectures face challenges in inter-domain trust and scalability. To address these issues, this paper proposes a blockchain-enabled trusted routing scheme for SDN inter-domain communication, denoted as BTR-SDN. First, a multi-dimensional model based on the Fuzzy Analytic Hierarchy Process (FAHP) is designed to quantify node trust values, and a sliding-window trust recovery mechanism with a time-decay factor is introduced to enable penalized nodes to regain trust through compliant behaviors gradually. Second, a trust-aware hierarchical topology reconstruction and route-pruning mechanism is introduced to adaptively adjust the network view and path selection strategy based on trust evaluation results. Third, to address scalability bottlenecks, we construct a layered “on-chain anchoring + off-chain storage” architecture. Critical trust proofs are anchored on-chain for attestation, while voluminous routing data is stored off-chain. Experimental results demonstrate that BTR-SDN achieves a 20.5% higher malicious node detection rate and improves bandwidth utilization by 10.7% compared to benchmark schemes, maintaining high throughput even under dynamic adversarial conditions.