[JGU]

Cryptology

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Lecture Notes
by Klaus Pommerening
Department of Mathematics and Medical School
Johannes Gutenberg University Mainz

FAQ Historical remarks Inventors References


Contents

  1. Classic Ciphers
  2. Bitblock Ciphers
  3. Asymmetric Ciphers
  4. Bitstream Ciphers

This an extended English version of the notes of cryptology courses I gave at Johannes Gutenberg University from 1988 until 2011 (when I retired).


Why this text? There exist already myriads of textbooks on cryptology, many of them excellent. An additional text should exhibit some original features. Here are some offerings of this text:

Requirements for readers: People without mathematical ambitions may browse the HTML pages—these are informal and hopefully self-contained. The mathematical background is always in PDF files whose substance differs from section to section, so there should be useful information on every level of mathematical sophistication. Large parts of the mathematical content of Chapter I are accessible with a good knowledge of school mathematics (calculating with numbers, naive probability). From Part II on almost all content is mathematical and requires some undergraduate mathematics (basic knowledge in calculus, probability, linear algebra, rings, fields, polynomials, algorithmics). After all, these lectures were given for students of mathematics and computer science. The methods of cryptography are mathematical. (David Kahn)

The mathematical formalism (here as elsewhere) is useful for

... as far as possible. Unfortunately there is ample room left for precision—lots of the mathematical foundations of modern cryptology are yet unprecise and use heuristics and handweaving.

Hints for mathematicians are on an extra page.

Notation:


Author: Klaus Pommerening, 1999-Sep-29; last change: 2021-Apr-17