Security Enhancement Using Mutual Authentication in Existing CDMA Systems

Even though CDMA2000 wireless networks are being widely deployed as a cellular digital standard around the world, it has some hidden vulnerabilities concerned with security issues. The existing CDMA systems use authentication mechanism by CAVE (Cellular Authentication and Voice Encryption) algorithm. This authentication method has several disadvantages. Only one way authentication is provided, that is, only a base station authenticates a subscriber. And, CAVE algorithm is prone to cryptographic attacks. This work proposes to implement authentication method using ESA (Enhanced Subscriber Authentication) algorithm instead of CAVE algorithm in the existing CDMA systems. Authentication mechanism using ESA algorithm uses AKA (Authentication and Key Agreement) to enhance security strength and to provide mutual authentication between a base station and a mobile terminal. AKA with 128-bit key adopts the SHA1 hash algorithm to generate authentication value and message encryption keys. Performance analysis of the proposed work is done by calculating the autocorrelation, crosscorrelation of the transmitted voice signal and also the BER (Bit Error Rate) of the system. Thus the proposed work enhances the security strength of the system with increased key strength and bilateral authentication. The proposed scheme can readily be applied to the existing CDMA systems because only the algorithm is replaced but the input parameters remain the same. Keywords—ESA, AKA, CAVE, CDMA, authentication