Codes and ciphers : Julius Caesar, the ENIGMA, and the Internet /
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| Author / Creator: | Churchhouse, R. F. |
|---|---|
| Imprint: | Cambridge, UK ; New York, NY : Cambridge University Press, 2002. |
| Description: | x, 240 p. : ill. ; 24 cm. |
| Language: | English |
| Subject: | |
| Format: | Print Book |
| URL for this record: | http://pi.lib.uchicago.edu/1001/cat/bib/4565752 |
Table of Contents:
- Preface
- 1. Introduction
- Some aspects of secure communication
- Julius Caesar's cipher
- Some basic definitions
- Three stages to decrytion: identification, breaking and setting
- Codes and ciphers
- Assessing the strength of a cipher system
- Error detecting and correcting codes
- Other methods of concealing messages
- Modular arithmetic
- Modular addition and subtraction of letters
- Gender
- End matter
- 2. From Julius Caesar to simple substitution
- Julius Caesar ciphers and their solution
- Simple substitution ciphers
- How to solve a simple substitution cipher
- Letter frequencies in languages other than English
- How many letters are needed to solve a simple substitution cipher?
- 3. Polyalphabetic systems
- Strengthening Julius Caesar: Vigenere ciphers
- How to solve a Vigenere cipher
- Indicators
- Depths
- Recognising 'depths'
- How much text do we need to solve a Vigenere cipher?
- Jefferson's cylinder
- 4. Jigsaw ciphers
- Transpositions
- Simple transposition
- Double transposition
- Other forms of transposition
- Assessment of the security of transposition ciphers
- Double encipherment in general
- 5. Two-letter ciphers
- Monograph to digraph
- MDTM ciphers
- Digraph to digraph
- Playfair encipherment
- Playfair decipherment
- Cryptanalytic aspects of Playfair
- Double Playfair
- 6. Codes
- Characteristics of codes
- One-part and two-part codes
- Code plus additive
- 7. Ciphers for spies
- Stencil ciphers
- Book ciphers
- Letter frequencies in book ciphers
- Solving a book cipher
- Indicators
- Disastrous errors in using a book cipher
- 'Garbo"s ciphers
- One-time pad
- 8. Producing random numbers and letters
- Random sequences
- Producing random sequences
- Coin spinning
- Throwing dice
- Lottery type draws
- Cosmic rays
- Amplifier noise
- Pseudo-random sequences
- Linear recurrences
- Using a binary stream of key for encipherment
- Binary linear sequences as key generators
- Cryptanalysis of a linear recurrence
- Improving the security of binary keys
- Pseudo-random number generators
- The mid-square method
- Linear congruential generators
- 9. The Enigma cipher machine
- Historical background
- The original Enigma
- Encipherment using wired wheels
- Encipherment by the Enigma
- The Enigma plugboard
- The Achilles heel of the Enigma
- The indicator 'chains' in the Enigma
- Aligning the chains
- Identifying R1 and its setting
- Doubly enciphered Enigma messages
- The Abwehr Enigma
- 10. The Hagelin cipher machine
- Historical background
- Structure of the Hagelin machine
- Encipherment on the Hagelin
- Choosing the cage for the Hagelin
- The theoretical 'work factor' for the Hagelin
- Solving the Hagelin from a stretch of key
- Additional features of the Hagelin machine
- The slide
- Identifying the slide in a cipher message
- Overlapping
- Solving the Hagelin from cipher texts only
- 11. Beyond the Enigma
- The SZ42: a pre-electronic machine
- Description of the SZ42 machine
- Encipherment on the SZ42
- Breaking and setting the SZ42
- Modifications to the SZ42
- 12. Public key cryptography
- Historical background
- Security issues
- Protection of programs and data
- Encipherment of programs, data and messages
- The key distribution problem
- The Diffie-Hellman key exchange system
- Strength of the Diffie-Hellman system
- 13. Encipherment and the internet
- Generalisation of simple substitution
- Factorisation of large integers
- The standard method of factorisation
- Fermat's 'Little Theorem'
- The Fermat-Euler Theorem (as needed in the RSA system)
- Encipherment and decipherment keys in the RSA system
- The encipherment and decipherment processes in the RSA system
- How does the key-owner reply to correspondents?
- The Data Encryption Standard (DES)
- Security of the DES
- Chaining
- Implementation of the DES
- Using both RSA and DES
- A salutary note
- Beyond the DES
- Authentication and signature verification
- Elliptic curve cryptography
- Appendix
- Solutions to problems
- References
- Name index
- Subject index
