Copyright © 2014 Bart Massey

These are some very simple, relatively untested Haskell tools to aid cryptanalysis of really unsophisticated ciphers. All tools leave characters outside the range 'A-Z' untransformed.

• transpose.hs: Given a count as an argument, transpose standard input to standard output with that spacing. Ignore newlines on input and produce 78-character lines on output.

• rot.hs: Show all 26 possible Caesar decryptions of the input, one per line.

• subst.hs: Try a very primitive frequency-table-based decryption of a general monalphabetic substitution cipher. Basically substitutes ETAONRISHD for the highest-frequency letters in the ciphertext in order, and translates all other alphabetics to '_'.

• vigenere.hs: Given the key as an argument, decrypt the given ciphertext as a Vigenère_cipher

This work is available under a "BSD License". Please see the file COPYING in this distribution for license terms.