The design of code and
cipher systems has undergone major
changes in modern times. Powerful personal computers have
resulted in an explosion of e-banking, e-commerce and
e-mail, and as a consequence the encryption of
communications to ensure security has become a matter of
public interest and importance. This book describes and
analyses many cipher systems ranging from the earliest and
elementary to the most recent and sophisticated, such as
RSA and DES, as well as wartime machines such as the
ENIGMA
and Hagelin, and
ciphers used by spies. Security issues and
possible methods of attack are discussed and illustrated by
examples. The design of many systems involves advanced
mathematical concepts and this is explained in detail in a
major appendix. This book will appeal to anyone interested
in
codes and ciphers as used by private individuals, spies,
governments and industry throughout history and right up to
the present day.
Contents
1. Introduction
2. From Julius Caesar to simple substitution
3. Polyalphabetic systems
4. Jigsaw systems
5. Two-letter ciphers
6. Codes
7. Ciphers for spies
8. Producing random numbers and letters
9. The ENIGMA cipher machine
10. The Hagelin cipher machine
11. Beyond the ENIGMA
12. Public key cryptography
13. Encipherment and the Internet
Appendix