Whirlwind Tour
of Math

Fall 2007
course
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Cryptography

Multiplication is easy, but factorisation is hard. (Factorising a number means breaking it up into prime divisors; for example, factorising 15 results in the answer 3×5 ). This observation lies behind many modern cryptography systems, including those used for credit card security on the internet. We'll see how this works, and how it compares to older cryptosystems.
Below are two files containing the encoded text of two first paragraphs of novels. A third file contains encoded quotations from the same author. In all cases a straight substitution code has been used and spaces and punctuation are omitted.
http://cs.marlboro.edu/ courses/ fall2007/math_tour/ Cryptography
last modified Thursday October 11 2007 12:54 pm EDT

attachments [paper clip]

     name last modified size
[TXT]encoded1.txt Oct 8 2007 1:33 pm 585B [TXT]encoded2.txt Oct 8 2007 1:33 pm 368B [TXT]quotes.txt Oct 11 2007 12:51 pm 309B