19.1 Preliminary remarks
On the most abstract level, a cryptographic protocol such as TLS can be viewed as a cryptographic system, that is, a system that utilizes cryptographic techniques to achieve certain protection goals.
In the present chapter, we will discuss various types of cryptographic attacks. However, we will not consider malware-based attacks (see https://en.wikipedia.org/wiki/Category:Cryptographic_attacks for a list of various attacks) on end systems where cryptographic algorithms are carried out. The reason for this is that we are mainly interested in the security of cryptographic algorithms, but not in the security of the computing platforms they are running on.
Basically, this means the security of cryptographic systems is evaluated based on the assumption that two important conditions are fulfilled:
There is some kind of secret – maybe shared, as in symmetric key cryptography, or maybe private, as in Diffie-Hellman key exchange – that is unknown to the...
