University of Virginia, Department of Computer Science
CS588: Cryptology - Principles and Applications, Fall 2001

Manifest: Monday 5 September 2001
Assignments Due
Monday, 10 SeptemberProblem Set 1
Monday, 1 OctoberProjects 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:  XFYYERXFOJYEPRVEWSRRRIGBSUXWRETGNMRI
Links
Questions

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.




CS 655 University of Virginia
Department of Computer Science
CS 588: Cryptology - Principles and Applications
David Evans
evans@cs.virginia.edu