STK: A Salted Temporal Key Scheme for Dynamic Swarm Security

Securing the reintegration of outlier nodes in dynamic UAV networks is challenging. This challenge arises from the lack of time-sensitive access control in existing key management schemes. We propose the Salted Temporal Key scheme (STK), which combines blockchain-based dynamic key management with temporal validation. This work addresses the absence of a time-sensitive admission policy by coupling reintegration cost to a UAV’s verifiable disconnection time: short-term outliers reintegrate quickly, while long-duration, high-risk outliers face increasing barriers. STK binds reintegration difficulty to the block-broadcast interval <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>τ</mi></semantics></math></inline-formula>, making reintegration a computational challenge proportional to the number of missed consensus cycles. Experiments on swarms with 50–100 nodes show that STK efficiently manages reintegration latency, providing scalable and adaptable security for decentralized UAV networks. The results demonstrate that by adjusting <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>τ</mi></semantics></math></inline-formula>, operators can isolate UAVs with excessive delays and ensure reliable swarm communication. STK offers a flexible, non-interactive solution, significantly enhancing security and scalability for UAV swarm reintegration in diverse environments.