Ralph Morelli, Ralph Walde
A genetic algorithm is used to find the keys of Type II periodic polyalphabetic ciphers with mixed primary alphabets. Because of the difficulty of the ciphertext only cryptanalysis for Type II ciphers, a multi-phased search strategy is used, each phase of which recovers a bigger portion of the key.
Subjects: 1.9 Genetic Algorithms; 15.7 Search
Submitted: Feb 12, 2006