Method and apparatus for access authentication in wireless mobile communication system

A method for Access Authentication in a wireless mobile communication system, the method comprising steps of:

• receiving a message from a terminal requesting access authentication at an Access Network Authentication, Authorization and Accounting server (AN-AAA) including identification, random text and a first authentication parameter;
• calculating a second authentication parameter with the random text by the AN-AAA using a Cellular Authentication and Voice Encryption Algorithm (CAVE) algorithm, if the terminal is in a dual mode;
• comparing the second authentication parameter with the first authentication parameter;
• and
• approving the access authentication if the compared result is passed;
• wherein the calculating step comprises calculating the second authentication parameter with the random text using a Message Digest 5 (MD5 ) algorithm if the terminal is a High Rate Packet Data (HRPD) single-mode terminal.

An apparatus for Access Authentication in a wireless mobile communication system comprising:

• an Access Network Authentication, Authorization and Accounting server (AN-AAA) for receiving a message from a terminal requesting access authentication including identification, random text and a first authentication parameter;
• calculating a second authentication parameter with the random text using a Cellular Authentication and Voice Encryption (CAVE) algorithm if the terminal is in a dual mode;
• comparing the second authentication parameter with the first authentication parameter;
• and approving the authentication if the compared result is passed;
• wherein the calculating step comprises calculating the second authentication parameter with the random text using a Message Digest 5 (MD5) algorithm if the terminal is a High Rate Packet Data (HRPD) single-mode terminal.