Method and system for authenticating terminal subscriber identity module in IP multimedia domain

A system for authenticating a terminal subscriber identity module in an IP Multimedia (IM) domain, comprising:

• User Equipment (UE), for initiating an IM domain register request;
• a Serving Call Session Control Function (S-CSCF), for sending an Authentication Vector (AV) request upon receiving the IM domain register request initiated by the UE, and interacting with the UE for a relative message for authenticating a terminal subscriber identity module of the UE upon receiving an AV;
• a Home Subscriber Server (HSS), for sending a request message for acquiring the AV upon receiving the AV request sent from the S-CSCF, wherein the process of sending the request message to the home device of the UE comprises:
• sending a Authentication Information Message containing the type of requesting node, and sending the AV to the S-CSCF;
• a home device of the UE, wherein an individual sequence number of each UE in the home device of the UE, SQNHE, comprises at least one SQNHE corresponding to at least one type of domain respectively, for allocating a Sequence Number (SQN) for the UE upon receiving the request message for acquiring the AV sent from the HSS, wherein the process of allocating the SQN for the UE comprises:
• determining the domain to which the HSS belongs according to the type of requesting node contained in the Sending Authentication Information Message, allocating the SQN for the domain to which the HSS belongs according to the SQNHE corresponding to the domain to which the HSS belongs, and generating the AV based on the SQN and sending the AV to the HSS.