CS588: Cryptology - Principles and Applications, Fall 2001 |
Manifest: Monday 5 September 2001
Assignments Due Monday, 10 September Problem Set 1 Monday, 1 October Projects Preliminary Proposal
Readings Read before 10 September: MBC, Chapter 6.
Vigenere Square
1 2 3 4 5 Count: 12345678901234567890123456789012345678901234567890123456 Plain: ThebiggerboysmadeciphersbutifIgotholdofafewwordsIusually Key: KEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKE Cipher: DLCLMEQIPLSWCQYNIASTFOVQLYRSJGQSRRSJNSDKJCGAMBHQSYQEEJVC 6 7 8 9 10 11 7890123456789012345678901234567890123456789012345678901234 Plain: foundoutthekeyTheconsequenceofthisingenuitywasoccasionally Key: YKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEY Cipher: DYYLNSSDXFOOCIXFOGMXWCAYCXGCYJRRMQSREORSSXWGEQYGAKWGYRYVPW 12 13 14 15 16 5678901234567890123456789012345678901234567890123456789 Plain: painfultheownersofthedetectedcipherssometimesthrashedme Key: KEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYK Cipher: ZEGXJSVXFOSUXIPCSDDLCNIROGROHASTFOVQCSKOXGWIQDLPKWFOHKO 17 18 19 20 012345678901234567890123456789012345 Plain: thoughthefaultlayintheirownstupidity - Charles Babbage (quoted in The Code Book) Key: YKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKE Cipher: XFYYERXFOJYEPRVEWSRRRIGBSUXWRETGNMRILinks
- Alex Biryukov's lecture notes on cryptanalysis of Enigma
- Alan Turing's Treatise on Enigma (1940, declassified in 1996)
- Bletchley Park
- Enigma Movie, Breaking the Code movie
- Password Recovery, Microsoft Money 2.0 and Quicken 3.0
Questions
- How to attack the Vigenere cipher
- How to calculate the keyspace for a mechanical cipher machine
- How to factor permutations that are products of involutions
Propose to an Englishman any principle, or any instrument, however admirable, and you will observe that the whole effort of the English mind is directed to find a difficulty, a defect, or an impossiblity in it. If you speak to him of a machine for peeling a potato, he will pronounce it impossible: if you peel a potato with it before his eyes, he will declare it useless, because it will not slice a pineapple.
Charles Babbage, breaker of Vigenere cipher, after losing funding for his Difference Engine project, 1823.
University of Virginia Department of Computer Science CS 588: Cryptology - Principles and Applications |
David Evans evans@virginia.edu |