I hope you enjoyed Ed’s guest posts on NP-complete problems on TV the last couple of Mondays. It’s always great to hear from others on math that they are thinking about. This week it’s me again, and ...

Welcome to Math Monday! Each Monday here at Casting Out Nines, we feature a mathematics-themed article. Today’s is a new installment in an ongoing virtual seminar on columnar transposition ciphers.

Split the Message into Characters Break the message into individual characters and create a list where each element is one character. Optionally, convert all characters to lowercase or uppercase for ...

Abstract: Single columnar transposition is an encryption technique used in text encryption to produce cipher text which is a permutation of its original text. In this study, cryptanalysis of Single ...

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This was one of the most secure hand ciphers used in the Second World War. It was used by both the Allies and the Axis, and served both well. Its main weakness was that if the attacker intercepted two ...

Abstract: Connect6 is an intuitive and fair game with no first-hand advantage. Because of the large search tree, the search depth is often lower, to sacrifice strength of chess to improve search ...