Method For A Secure Detach Procedure In A Radio Telecommunication Network

A method for performing a detach of a terminal registered to a telecommunication network is disclosed. The detach is performed by associating an identification for the terminal, deriving a signature for the identification, and allocating a pair consisting of the identification and the signature to the terminal. The method further includes sending the detach request including the identification and the identification signature from the registered terminal to the network. The detach request is received at the network and compared to a record of registration data of the terminal kept at the network. The terminal is detached from the network if the received detach request coincides with the record of registration data.