Abstract: A method of performing biometric authentication with a mobile station having a camera, front side display and integrated authentication server, or is connectable to an authentication server via a mobile communications network, includes: enrolling the user in a biometric system by capturing and storing biometric data relating to a plurality of characteristics of the user's head normally exposed to the mobile station during the process of accepting a call; activating the camera when initiating, receiving, or accepting a call and capturing optical information in one or a plurality of sequences at least between the setup or acceptance of the call and the start of the conversation and transferring the captured optical information to the authentication server; authenticating the user by comparing the optical information with the biometric data previously captured, by identifying and matching characteristics captured from different angles; and performing defined actions as a result of the authentication.