Multiple authentication

Authentication is one of the fundamental security mechanisms in computer science applications. Users can have access to the systems after authentication process is performed. Due to the easy use, passwords are mostly used for authentication. However, people encounter some problems with passwords in real life situations. One of the problem is users need to memorize and remember lots of passwords for distinct services. Unfortunately, rather than using disparate passwords, users generally prefer to use the same passwords for distinct services. Using the same password for different services give rise to security vulnerabilities. At this point, the question ?Can we manage relatively strong and different passwords via a unique password?? arises.In the scope of this study, an ancient theorem which is called Chinese Remainder Theorem was used to solve the problem. Firstly, a unique password was obtained from pre-defined passwords. But, since this unique password is very long and very difficult to memorize, another method has been developed. According to the second method, a unique password is defined by the user in advance then distinct and strong passwords are generated from the unique password. Finally, a secure multiple authentication protocol which is based on Chinese remainder theorem have been developed and the security analysis of the protocol have been done.