A CRYPTOGRAPHIC KEY GENERATING METHOD, DEVICE AND SYSTEM

摘要

A cryptographic key generating method, device and system are provided, wherein, the method is used for generating a cryptographic key in the process of the user equipment switching to an EUTRAN (Evolved UTMS (Universal Mobile Telecommunication System) Terrestrial Radio Access Network) network from the other network, the method includes: a MME (Mobile Management Entity) generates a cryptographic key based on a root cryptographic key KASME (Kay Access Security Management Entity) of the EUTRAN network and a special value and/or other parameters and sends a switch request message carrying the cryptographic key to a target evolved Node-B, i.e. eNB (evolved Node-B); a UE (user equipment) generates the cryptographic key which will be used by the target eNB based on the root cryptographic key KASME of the EUTRAN network and the special value and/or other parameters. The application of the present invention adopts a special value and KASME and/or other parameters to output a cryptographic key, which can solve the problem existed in the related technology, the problem is that the middle cryptographic key used by access layer while switching between different access system couldn't be generated, and then it could not realize the safety protection of the access layer. So the application of the present invention makes the signaling and/or data of the access layer be efficiently protected, thereby improving the safety of the access layer.