Method and system for supporting authentication and security protected non-access stratum protocol in mobile telecommunication system

PURPOSE: A management method and a system for supporting a NAS(Non- Access Stratum) protocol security are provided to efficiently operate the mobility of a terminal, a location management and a registration management by using a method for efficiently processing the secured NAS message. CONSTITUTION: The front part of a AKA(Authentication and Key Agreement) authentication procedure is operated(401). A MME(Mobility Management Entity) decides whether to transmit an authentication request message or a NAS security mode authentication to a terminal(403). An authentication response message is received from the terminal(423). The MME decides a response from a corresponding terminal by comparing an expected response with a response(425). A security mode command message is transmitted from the MME to the terminal(427). A security mode complete message is received from the terminal(429).