Patent ID: 9713001
Date: 2017-07-18
CPC Classifications: H04L,H04W

Claim:
1. A method for generating an identifier of a key, comprising: when a User Equipment (UE) transfers from an Evolved UMTS Terrestrial Radio Access Network (EUTRAN) to a Global System for Mobile Communications (GSM) or to an enhanced data rate for GSM Evolution Radio Access Network (GERAN), generating, by a Mobility Management Entity (MME), an identifier of a ciphering key and an integrity key by mapping a key set identifier for an access security management entity, and sending the ciphering key, the integrity key and the identifier thereof to a Serving GPRS Support Node (SGSN); assigning, by the SGSN, a value of the identifier of the ciphering key and the integrity key to an identifier of a ciphering key of the GSM or GERAN, wherein the identifier of the ciphering key of the GSM or GERAN is a sequence number of the ciphering key; and generating, by the UE, an identifier of the ciphering key of the GSM or GERAN by mapping the key set identifier of the access security management entity; wherein the generating by mapping comprises: assigning, by the MME, the value of the identifier of the ciphering key and the integrity key to be a value of the key set identifier of the access security management entity, or to be a sum of the value of the key set identifier of the access security management entity and a constant which is appointed by the UE and a network side; and assigning, by the UE, the value of the identifier of the ciphering key of the GSM or GERAN to be the value of the key set identifier of the access security management entity, or to be the sum of the value of the key set identifier of the access security management entity and a constant which is appointed by the UE and the network side.