METHOD, DEVICE AND SYSTEM FOR DEDUCING KEYS

摘要

A method, a device and a system for deducing keys used in the field of mobile communication technology. The method is used in the process of switching the user equipment from an evolved universal terrestrial radio access network (EUTRAN) to a universal terrestrial radio access network (UTRAN). In the second switching process because of the failed first switching, the method changes the input parameters used for deducing the keys, such as the methods of generating random values, changing the current downlink non-access stratum counter values and obtaining the fresh parameters computed by the user equipment etc., to ensure that the deduced keys in the resource mobility management entity during the user equipment's first switching process are different from the deduced keys in the mobility management entity during the user equipment's second switching process. The situation in the prior art that the keys of other Radio Network Controller (RNC) can be deduced by the keys of one of the RNCs is avoided, and the security of the network is strengthened.