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Mechanising Cryptography. Professor Richard Walton CB. Cryptography is concerned with the application of technology to the problem of encrypting and decrypting a message. The Mathematics is subordinate to the technology. 20 th Century Cryptography. Development of Crypt in the 1900s
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Mechanising Cryptography Professor Richard Walton CB
Cryptography is concerned with the application of technology to the problem of encrypting and decrypting a message. The Mathematics is subordinate to the technology
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
Security Usability Cost CRYPTOGRAPHY Balance Cost Cost
Cryptanalysis 1918 • Knowledge of language • Frequency Analysis • Key Re-use (Depth) Skill Requirement: To solve crossword puzzles in foreign languages
Enigma Army Navy – 4 wheel Navy
Early Machine Cryptography • Limitations of Security Design • Balance Security against Cost • Usability – Human Factors
Electronics – 1960-1980 • Shift Registers and Simple Logic Gates • Linear Algebra • Galois Theory • Rich Mathematical structure • Rigorous Analysis • Expensive Components
Large Scale Integration • Application Specific Integrated Circuits • Complex Algorithms • Tailored to purpose • Standard Cryptographic Primitives • Software and Firmware
Public Key Cryptography • Key Management • Non-Secret Encryption • Ellis, Cocks & Williamson • Beyond 1970’s technology • Widespread after 1985 • Search for easier solutions • Elliptic Curve Cryptography
Next Challenge Quantum Computers destroy current Public Key algorithms Find new algorithms to resist Quantum Computer attacks
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/