Cryptology for Beginners - MasterMathMentor.com

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Cryptology for Beginners Stu Schwartz Wissahickon High Ambler, Pa 19002. 1. Introduction and Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. 2. Monoalphabetic Substitution Ciphers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. A. The Additive (or shift) Cipher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. B. Modular Arithmetic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7. C. The Multiplicative Cipher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9. D. The Affine Cipher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12. 3. Polyalphabetic Substitution Ciphers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17. A. Integer Matrices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17. B. The Hill Digraph Cipher.

Cryptology for Beginners - 3 - www.mastermathmentor.com - Stu Schwartz Ciphertext - the secret version of the plaintext. So the plain text: iwillmeetyouatfivepminthemall may be changed to: NBNQQRJJYDTZFYKNAJURNSYMJRFQQ To make reading the ciphertext easier, the letters are usually written in blocks of 5.