RADAR: Robust aggregation with dynamic adversarial-resilient routing decentralized federated learning
摘要
Decentralized Federated Learning enhances privacy by removing central servers, but this architecture is susceptible to model poisoning and sophisticated network-level attacks. The Byzantine-robust BALANCE algorithm is a key defense against malicious updates, but this defense breaks down and halts learning if a network-level attack can feed a node a supermajority of malicious models. To counter this fundamental vulnerability, we introduce RADAR: Robust Aggregation with Dynamic Adversarial-Resilient Routing for such systems. The primary contribution of our RADAR framework is its use of Dynamic Adversarial-Resilient Routing-implemented as a proactive Moving Target Defense to protect its Robust Aggregation core. By creating an unpredictable network topology, RADAR prevents the network-level conditions that disable BALANCE, denying adversaries the sustained dominance required to overwhelm a node. Furthermore, RADAR enhances standard Moving Target Defense by replacing simplistic, deadlock-vulnerable random peer selection with a more secure, adaptive and unpredictable neighbor selection protocol. Communication integrity is further ensured through the use of Transport Layer Security, which provides robust encryption and protection against man-in-the-middle attacks. Importantly, our experimental results confirm that the integration of these techniques simultaneously preserves the efficiency and benefits of the aggregation rule, as demonstrated by an average F1 score of 0.92, representing the most secure configuration under model poisoning attacks-while imposing no significant overhead on system performance, with CPU and RAM usage increasing by only 2-3%, as well as approximately 45% reduced network traffic compared to the baseline.