Introduction to Cryptanalysis of Symmetric Ciphers

Objectives and Content:

The course gives an introduction to cryptanalysis. Roughly, the goal of cryptanalysis is given a siffer-text find the plain-text. Basic cryptanalytic attacks against symmetric ciphers are introduced.

Content:

The course contains three chapters. The historical ciphers chapter deals with analysis of various substitution and transposition ciphers, Hagelin cipher, and Geheimschreiber. The stream ciphers part contains time-memory trade-offs, attacks based on Berlekamp-Massey algorithm, correlation and algebraic attacks, 2-adic cryptanalysis. The block cipher chapter explains meet-in-the-middle attacks and linear and differential cryptanalysis.

On completion of of the course the student should have the following learning outcomes in terms of knowledge, skills and general competence:

Knowledge
The student

• should have knowledge of mathematical foundations of symmetric ciphers security,
• should have knowledge of basic algebra and probability theory applications in cryptanalysis,
• should have knowledge of how basic cryptanalytic attacks work.

Skills
The student

• is able to explain mathematical foundations of the security of ciphers
• digest and explain how cryptographic primitive work
• implement basic cryptanalytic attacks

General competence
The student

• is familiar with new ideas and innovation processes
• can exchange opinions with others with relevant background and participate in discussions concerning the development of good practice.