Data Protection and Security

VII

Identification and Entity Authentication

VII.II

Passwords

The phrase password-based authentication refers to the procedure that involves a secret quantity (the password) that you state to prove you know it.

If used alone, passwords are the least secure way of authenticating people. Then why is this method still preferred in many applications including highly security sensitive ones?

The answer can be summarized as follows:

• Username-password scheme is easy to implement because it has a simple structure.
• It is very easy to use from users’ perspective.
• It is inexpensive compared to other authentication schemes. While the others depend on specialized hardware devices, this method can be fully utilized by using only software techniques. This is why sometimes it is called "software authentication".

Due to its high popularity, in this section we discuss in detail various aspects of password based authentication schemes.