| 摘要 |
<p>A method of controlling a network entity ( 4, 4 ) 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 (S 21 ) whether a received message from the mobile station is encrypted. If the received message is encrypted, it is determined (S 22 ) 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 (S 33 ) 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 (S 34 ) an encryption key generation procedure.</p> |
