Appendix of RECESS A Additional Related Works A.1 Federated Learning

The aggregation gradient is a weighted average of each client's upload gradient, and the weight is determined by the number of However, the aggregation gradient, i.e., the global model, is vulnerable to poisoning From the perspective of the attacker's goal, poisoning attacks are categorized as targeted and untar-geted attacks. Note that Mkrum is Krum when m = 1, and Mkrum is FedAvg when m = n . FL Trust involves the server with a small dataset to participate in each iteration and generate a gradient benchmark in each iteration. FL Trust would discard benign outliers. All clients just follow normal FL training without any extra rules to obey.