3-Level Password Authentication System
In the current state there are many authentication schemes and most of these suffer from many weaknesses. Some of them are based on the physical and behavioral properties of the user, and some others are based on knowledge of the user such as textual and graphical passwords. Furthermore, there are other authentication schemes that are based on tokens, such as smart cards i.e., based on what the users have. Among the various authentication schemes, the most commonly used schemes are textual password and token-based schemes, or the combination of both. However, both these authentication schemes are vulnerable to certain attacks.