Method for a secure detach procedure in a radio telecommunication network

Discloses are systems, methods, devices, including a method for performing a detach of a terminal registered to a telecommunication network by associating an identification for the terminal, deriving a signature for the identification, and allocating a pair containing the identification and the signature to the terminal. The method includes sending a detach request including the identification and the identification signature from the registered terminal to the network, receiving the detach request at the network side, comparing the received detach request with a record of registration data of the terminal kept at the network side, and detaching the terminal from the network if the received detach request coincides with the record of registration data.