An information processing method and apparatus, an information retrieval method and apparatus, a user terminal, and a server are provided. The retrieval method includes receiving, by a first user terminal, information from a second user terminal, about an address used to save an encrypted file of the second user terminal, acquiring, from a cloud server and a trusted server, privacy information, non-privacy information, and a shared key that correspond to the address information, obtaining address information of a to-be-accessed file by searching the privacy information and the non-privacy information, acquiring, from the cloud server, a first encrypted file corresponding to the address information of the to-be-accessed file, and decrypting the first encrypted file by using the shared key, to obtain the to-be-accessed file.