An application of the theory of permutations in breaking the Enigma cipher
Marian Rejewski · Applicationes Mathematicae · 1980
The present paper is intended to show, necessarily in great brevity and simplification, some aspects of the Enigma cipher breaking, those in particular which used the theory of permutations. This paper, being not a systematic outline of the process of breaking the Enigma cipher, presents however its important part.