Extension of Authentication Protocol for GSM

[[abstract]]An extension of the authentication protocol for GSM is proposed to improve some drawbacks of the current GSM authentication protocol including: not supporting bilateral authentication; huge bandwidth consumption between VLR and HLR; stored space overhead in VLR; and overloaded HLR with authentication of mobile stations. As a result, this new extension of the authentication protocol not only improves these drawbacks but also achieves the requirements: mutual authentication, reduction of bandwidth consumption, less storage of VLR database, security, and efficiency. The merit of the proposed protocol is that it does not cause problems and alter the existing architecture of GSM at all. The robustness of the new protocol is also based on security algorithms A3, A5 and A8