A Wolf in Sheep’s Clothing: Unveiling a Stealthy Backdoor Attack in Subgraph Federated Learning

Subgraph Federated Learning (FL, a system where pieces of a graph are distributed across multiple devices to protect data privacy) is vulnerable to backdoor attacks (hidden malicious functions that cause a model to behave incorrectly when triggered). Researchers developed BEEF, an attack method that uses adversarial perturbations (carefully crafted small changes to input data that fool the model) as hidden triggers while keeping the model's internal parameters unchanged, making the attack harder to detect than existing methods.