Access Authentication in CDMA networks a.k.a. CAVE-based Authentication (IS-95/1xRTT), A12 Authentication (1xEV-DO) Authentication of a mobile device by the serving access network. The access authentication mechanism employed depends upon the type of service being used:

• CAVE-based Authentication Used for access authentication in CDMA/1xRTT
• AKA 3G successor to CAVE-based authentication
• A12 Authentication Used for access authentication in 1xEV-DO

Note that 1xEV-DO Hybrid MS/AT devices may employ both CAVE-based and A12 authentication since these devices connect to both the 1xRTT and 1xEV-DO networks.