Method and system for user authentication by means of a cellular mobile radio network

A system for authentication of a user at an access device by means of a cellular mobile radio network, comprising an access device and a cellular mobile radio network, the access device giving access to a facility or a service different from the mobile radio network, the cellular mobile radio network comprising a base station defining a mobile radio cell with a unique identifier, the system further comprising a mobile radio terminal having a unique identifier and being able to book into the mobile radio network via said base station, the system being able to carry out the authentication by means of the identifier of the mobile radio cell and the identifier of the mobile radio terminal, wherein the base station is arranged at the location of the access device so that the access device has its own mobile radio cell serviced by the base station, this mobile radio cell defining an authentication cell of the mobile radio network, and that the system is arranged to cause the mobile radio terminal to book into the mobile radio network via said base station of said authentication cell for the purpose of authentication at the access device, the system further comprising an authentication entity for receiving the identifiers and checking whether the user is permitted to get access at the access device and a receiving device for receiving a user input or for recording identification data of a user, the receiving device serving to contactlessly transmit the user input or the identification data to the access device or another device for further authentication.