SUALPPA Scheme: Enhanced Solution for User Authentication in the GSM System

The Global System for Mobile Communications (GSM) is the most popular standard for mobile phones in the world. GSM phones are used by over the billion people across more than 200 countries. In spite of the tremendous market growth, however, there are major security drawbacks in the GSM system. In this paper, we introduce the secure user authentication scheme to solve the problem: user authentication and location privacy. Also the proposed scheme provides partial anonymity, because of the usage of temporary identity and the new mechanism that the only authenticated VLR can use the MS's IMSI. Besides, we introduce the modified scheme to reduce user authentication procedure without changing of the architecture of the original GSM system.