VFedAD: A Defense Method Based on the Information Mechanism Behind the Vertical Federated Data Poisoning Attack
Jinrong Lai, Tong Wang, Chuan Chen, Yihao Li, Zibin Zheng · 2023
In recent years, federated learning has achieved remarkable results in the medical and financial fields, but various attacks have always plagued federated learning. Data poisoning attack and defense research in horizontal federated learning are sufficient, yet vertical federated data poisoning attack and defense remains an open area due to two challenges: (1) Complex data distributions lead to immense attack possibilities, and (2) defense methods are insufficient for complex data distributions. We have discovered that from the perspective of information theory, the above challenges can be addressed elegantly and succinctly with a solution. We first reveal the information-theoretic mechanisms underlying vertical federated data poisoning attacks and then propose an unsupervised vertical federated data poisoning defense method (VFedAD) based on information theory. VFedAD learns semantic-rich client data representations through contrastive learning task and cross-client prediction task to identify anomalies. Experiments show VFedAD effectively detects vertical federated anomalies, protecting subsequent algorithms from vertical federated data poisoning attacks.