Classical Cryptography

Corresponding entry in Aachen Campus, Bonn Computer Science, Bonn Mathematics, Bonn University.

Lecture

Prof. Joachim von zur Gathen

Tutorial

Jérémie Detrey

Time & Place

Monday, 15⁰⁰-15⁴⁵, b-it bitmax.
Wednesday, 15¹⁵-16⁴⁵, b-it bitmax.
Tutorial: Monday, 13¹⁵-14⁴⁵, b-it bitmax.

First meeting: Monday, 07 April 2008, 15⁰⁰,b-it bitmax.
Exam: Thursday, 31 July 2008, 15⁰⁰-18⁰⁰,b-it bitmax.

Allocation

3+2 SWS, 6 credits.

Media Informatics: Computer and Communication Technology.
Recommendation for University of Bonn - Computer Science: A or A1, respectively.

Prerequisites

None.

This course deals with classical methods of cryptography and cryptanalysis. This starts with simple substitutions and the Vigenère cipher, broken by Kasiski's method. Frequency analysis is developed into Shannon's theory of entropy. The German cipher machine Enigma from the Second World War is explained, with the breaks by Polish and British cryptanalysts, which changed the course of the war. The world's first electronic computer Colossus was invented as a tool for breaking another German system, the Geheimschreiber.

Lecture notes

Here: pdf.

Tutorials

Tutorial 1: Substitutions and transpositions.
- Exercise sheet: pdf.
Tutorial 2: Rivest, Shamir and Adleman.
- Exercise sheet: pdf.
Tutorial 3: Information entropy.
- Exercise sheet: pdf.
Tutorial 4: The Enigma.
- Exercise sheet: pdf.
Tutorial 5: Cryptanalysis of the Enigma.
- Exercise sheet: pdf.