Authentication and digital signatures
In cryptography, the authentication problem is one of the most interesting and difficult problems to solve. Authentication is one of the most sensitive functions (as well as the most used) for the procedure of access control.
Authentication is based on three methods:
- Something that only the user knows (for example, a password)
- Something that only the user holds (a smart card, device, or token)
- Something that characterizes the user (for example, fingerprints, an iris scan, and other general biometric characteristics of a person)
An authentication method based on digital signatures. Keep in mind (as we will see later on) that there are similar methods of authentication based, for example, on zero knowledge, which will be covered further in Chapter 5, Zero-Knowledge Protocols.
Let’s see how a method of authentication based on a digital signature over public/private key encryption works.
Let’...
