University of Virginia, Department of Computer Science
CS551: Security and Privacy on the Internet, Fall 2000

Manifest: Monday 4 September 2000
Assignments Due
Monday, 11 SeptemberProblem Set 1
Monday, 18 SeptemberProjects Preliminary Proposal

Readings
Read before 6 September: Stallings, Chapter 3.

Optional reading for more information: (see web version for links)

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
Key:     YKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKEYKE
Cipher:  XFYYERXFOJYEPRVEWSRRRIGBSUXWRETGNMRI

Charles Babbage (quoted in Simon Singh,
The Code Book : The Evolution of Secrecy from Mary, Queen of Scots to Quantum Cryptography, 1999)

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 551: Security and Privacy on the Internet
David Evans
evans@cs.virginia.edu