5
Entity Authentication
In Chapter 2, Secure Channel and the CIA Triad, we saw that Alice and Bob need the CIA triad – the combination of the cryptographic goals confidentiality, integrity, and authentication – to establish a secure communication channel in the presence of both passive and active attackers. We defined what authentication is, gave several examples illustrating what happens when authentication goes wrong, and briefly discussed the two types of authentication used in cryptography, namely message authentication and entity authentication.
In this chapter, we are going to cover authentication – in particular entity authentication – in much more detail. Particularly, we will discuss the following:
Why entity authentication is absolutely necessary to establish a secure channel
The mathematical properties of cryptographically secure authentication
Why password-based authentication is rather weak
Several types of cryptographic protocols for strong...
