This application discloses a communication method and apparatus, a storage medium, and a program product. The method includes: A server sends training information. The training information includes a global model in a previous round and identifiers of at least two second terminals that participate in a current round of training. A first terminal sends a local model of the first terminal. The local model is obtained based on the global model in the previous round and a shared key. The server receives local models of the at least two second terminals, and aggregates the local models of the at least two second terminals based on a shared key between the at least two second terminals, to obtain an updated global model in the current round. According to the solutions of this application, security in a neural network training process is improved.