Patent ID: 10028141

Abstract:
A method and system for determining that a SIM and a SIP client are co-located in the same ME. A SIP server, an SLR, and the ME are communicatively interconnected in the system. The SIM has an IMSI and is arranged in the ME. In the method and system, a security module, SLM-SM, included in SIM, encrypts, using a key, a variable derived from the IMSI, and provides a first password parameter as a result of the encrypting. Further, a SIP client location manager, SLM, included in the ME, receives the ME security code; performs an XOR operation of the ME security code and the identity of the ME, and provides a second password parameter as a result of the XOR operation. The SLR performs a process for SIP client presence and location update for mobile operators MSISDN, including receiving the second password parameter from the SLM via the SIP server, decrypting the second password parameter using the key, performing an XOR-operation of the decrypting result with a seed; comparing the result of the XOR-operation with the IMSI, and upon match, determining that the SIM and the SIP client are co-located in the same ME.