Mitigating drawbacks of ciphering failures in a wireless network

A wireless communication device for communicating with a general packet radio service, GPRS, wireless network, the wireless communication device comprising radio frequency, RF, circuitry, a processor and a memory, said memory containing instructions executable by said processor whereby said wireless communication device is operative to:

• receive, in a logical link control, LLC, entity in the wireless communication device, enciphered downlink data from a LLC entity in the wireless network,
• determine, in the LLC entity in the wireless communication device, that the enciphered downlink data cannot be deciphered,
• provide, from the LLC entity in the wireless communication device as a consequence of the determination that the enciphered downlink data cannot be deciphered, a ciphering failure indicator to a GPRS mobility management, GMM, entity in the wireless communication device,
• receive, in the GMM entity in the wireless communication device, the ciphering failure indicator and, as a consequence of the reception of the ciphering failure indicator in the GMM entity in the wireless communication device, providing an authentication procedure trigger from the GMM entity in the wireless communication device to a GMM entity in the wireless network, and
• operate an authentication procedure wherein the GMM entity in the wireless communication device communicates with a GMM entity in the wireless network via the respective LLC entities in the wireless communication device and the wireless network, whereby the LLC entity in the wireless communication device obtains information including identification of a security context comprising a security key for enabling enciphering and deciphering in subsequent communication between the LLC entity in the wireless communication device and the LLC entity in the wireless network.

A nontransitory computer readable storage medium, comprising instructions which, when executed on at least one processor in a wireless communication device, cause the wireless communication device to carry out a method when communicating with a general packet radio service, GPRS, wireless network, the method comprising:

• receiving, in a logical link control, LLC, entity in the wireless communication device, enciphered downlink data from a LLC entity in the wireless network,
• determining, in the LLC entity in the wireless communication device, that the enciphered downlink data cannot be deciphered,
• providing, from the LLC entity in the wireless communication device as a consequence of the determination that the enciphered downlink data cannot be deciphered, a ciphering failure indicator to a GPRS mobility management, GMM, entity in the wireless communication device,
• receiving, in the GMM entity in the wireless communication device, the ciphering failure indicator and, as a consequence of the reception of the ciphering failure indicator in the GMM entity in the wireless communication device, providing an authentication procedure trigger from the GMM entity in the wireless communication device to a GMM entity in the wireless network, and
• operating an authentication procedure wherein the GMM entity in the wireless communication device communicates with the GMM entity in the wireless network via the respective LLC entities in the wireless communication device and the wireless network, whereby the LLC entity in the wireless communication device obtains information including identification of a security context comprising a security key for enabling enciphering and deciphering in subsequent communication between the LLC entity in the wireless communication device and the LLC entity in the wireless network.