SECURITY KEY DERIVATION IN DUAL CONNECTIVITY Russian patent published in 2018 - IPC H04W12/04 H04L29/06 

FIELD: radio engineering and communications.

SUBSTANCE: invention relates to mobile communication. Method for establishing a secure communication link between a mobile station and a secondary base station in a mobile communication system, comprising the mobile station, a master and the secondary base station, the mobile station being initialised for communication with the master and the secondary base station, comprising: detecting, by the master or by the secondary base station, a potential security breach, including a condition where a sequence counter of packet data units of an established secure communication link between the mobile station and the secondary base station is to wrap-up since initialisation of the communication between the mobile station and the secondary base station, and a condition where a communication link identification is to be reused for establishing the secure communication link with the secondary base station since initialisation of the communication between the mobile station and the secondary base station; and, in case the potential security breach is detected by the secondary base station, signaling the detected security breach to the master base station; incrementing, by the master base station, in response to the detected or signaled potential security breach, a freshness counter for re-initialising the communication between the mobile station and the secondary base station; and re-initialising, by the mobile station and by the secondary base station, the communication there between, the re-initialising step being performed under the control of the master base station and further includes a step of deriving an identical security key based on said incremented freshness counter, and establishing the secure communication link using the identical, derived security key.

EFFECT: technical result is the establishment of a secure communication link between a mobile station and a secondary base station in a mobile communication system.

32 cl, 16 dwg