Mechanising Cryptography

1
Mechanising Cryptography

• Professor Richard Walton CB

2
Cryptography is concerned with the application of
technology to the problem of encrypting and
decrypting a message. The Mathematics is
subordinate to the technology
3
20th Century Cryptography

• Development of Crypt in the 1900s
• Manual Methods
• Slow
• Laborious
• Error-Prone
• Need to mechanise
• Importance of technology for design
• Nature of technological constraints

4
CRYPTOGRAPHY
Balance
Cost
Cost
5
Cryptanalysis 1918

• Knowledge of language
• Frequency Analysis
• Key Re-use (Depth)

Skill Requirement To solve crossword puzzles in
foreign languages
6
Rotor Machines
7
Rotors
8
Commercial Enigma
9
Enigma
10
Enigma
Army
Navy 4 wheel
Navy
11
(No Transcript)
12
(No Transcript)
13
Early Machine Cryptography

• Limitations of Security Design
• Balance Security against Cost
• Usability Human Factors

14
Electronics 1960-1980

• Shift Registers and Simple Logic Gates
• Linear Algebra
• Galois Theory
• Rich Mathematical structure
• Rigorous Analysis
• Expensive Components

15
Large Scale Integration

• Application Specific Integrated Circuits
• Complex Algorithms
• Tailored to purpose
• Standard Cryptographic Primitives
• Software and Firmware

16
Public Key Cryptography

• Key Management
• Non-Secret Encryption
• Ellis, Cocks Williamson
• Beyond 1970s technology
• Widespread after 1985
• Search for easier solutions
• Elliptic Curve Cryptography

17
Next Challenge
Quantum Computers destroy current Public Key
algorithms Find new algorithms to resist
Quantum Computer attacks
18
(No Transcript)
19
Mechanising Cryptography
Acknowledgement Illustrations concerning Enigma
in this presentation have been taken from the
user manual for Enigma E by Paul Reuvers Marc
Simons. For details of Enigma-E, which is
available for purchase from Bletchley Park
Museum, see www.xat.nl/enigma-e/