An encryption method implemented by a terminal having an operating system that can be accessed by several users and an encryption module for encrypting data intended for another terminal. The method includes a detection step for detecting when a session for accessing the operating system is opened by a user. In response to the detection of such a session being opened, the method continues with a step of setting the parameters of the encryption module with an encryption key unique to the user for encrypting data intended for another terminal, in which the encryption key is generated by the terminal, or is stored in a memory of the terminal before the detection of a session accessing the operating system being opened.