The invention concerns a method for the authentication of users of a hybrid terminal with a first registration step. The first registration step comprises entry of user identification data, request to enter a personal identification number, forwarding of the personal identification number to a registration server of an authentication apparatus, forwarding of the user identification data, validation of the user identification data, generation of a registration code, and in the event that entry of the personal identification number has not taken place, generation of the personal identification number, forwarding of the registration code to the internet-capable terminal and in the event that entry of the personal identification number has not taken place, forwarding of the personal identification number via a separate connection to the user. The method also comprises an authentication step comprising checking whether a profile file is present on the hybrid terminal, carrying out an authentication in order to establish whether the user is authorized to receive user data from the service provider and/or to send user data to the service provider, or otherwise carrying out an initial authentication and, if necessary, generation and transfer of the profile file. Furthermore, the invention concerns a corresponding apparatus for carrying out the method.