This paper proposes a mutual authentication technique for use in the wireless mobile network. Authentication of mobile subscribers is a challenging issue due to increasing security threats as it acts as the first defence against attackers. We come up with a novel authentication mechanism, called Group Registration, which reduces the huge bandwidth consumption between Visitor Location Register (VLR) and HLR; and overloaded Home Location Register (HLR) makes it suitable for low-power mobile devices. An efficient and secured channel is developed in the cryptosystems implementing the encryption function and keyed one-way function by cryptographic library JCE (Java Cryptography Extension) API in Java. Encryption function is implemented by symmetry-based AES encryption algorithm. The Keyed one-way function which follows HMAC standard (RFC 2104) is implemented by secure hash function SHA-2.