| 摘要 |
<p>A method of controlling a network entity (4, 5) of a mobile communication network and a mobile station (1) is described, as well as a corresponding mobile station and network entity. The network entity (4, 5) and the mobile station (1) are arranged to conduct a plurality of predetermined message exchange procedures in the course of which predetermined messages are exchanged between said network entity (4, 5) and said mobile station (1) depending on the given procedure. The predetermined messages may be encrypted, an encrypted message being any message of which at least a part is encrypted. The network entity (4, 5) and the mobile station (1) are furthermore arranged to conduct one or more encryption key generation procedures in parallel during which the network entity (4, 5) and the mobile station (1) generate and store respective corresponding encryption keys, in order to be able to encrypt and decrypt exchanged messages. The method comprises a step of determining (S21) whether a received message from the mobile station is encrypted. If the received message is encrypted, it is determined (S22) whether a correct encryption key for decrypting said message is available to said network entity (4, 5), and if no correct key is available, a predetermined triggering message is sent to said mobile station (1). The mobile station (1) then interrupts (S33) the procedure in the course of which it sent the encrypted message for which the network entity (4, 5) did not have a correct key, and initiates (S34) an encryption key generation procedure.</p> |
