Patent ID: 7607013

Claim:
A method for Access Authentication in a wireless mobile communication system, the method comprising steps of: determining, by an Access Network Authentication, Authorization and Accounting server (AN-AAA) a type of a terminal requesting access authentication according to one or more parameters in a message received from the terminal; selecting a Cellular Authentication and Voice Encryption (CAVE) algorithm or a Message-Digest 5 (MD5) algorithm by the AN-AAA, according to the terminal type; calculating a first authentication parameter by the AN-AAA, using the selected algorithm; comparing the first authentication parameter with a second authentication parameter received from the terminal; and approving an access authentication if the compared result is passed; wherein the calculating step comprises calculating the first authentication parameter with the CAVE algorithm if the terminal is in a Code Division Multiple Access 2000 (CDMA2000)/High Rate Packet Data (HRPD) dual-mode terminal, and calculating the first authentication parameter with the MD5 algorithm if the terminal is a High Rate Packet Data (HRPD) single-mode terminal.