Enigma Cryptanalysis - Beginnings Gaurish Korpal∗
[email protected] July 15, 2015 Abstract Any message may be hidden in two basic ways. The methods of steganography conceal the very existence of the message, for example invisible inks and microdots. The methods of cryptography, on the other hand, do not conceal the presence of a secret message but render it unintelligible as ciphertext, to outsiders by various transformations of the plaintext. Breaking ciphers require ingenuity, creativity and a little math. In this article our focus will be on breaking Enigma ciphers. The skill involved in breaking ciphers is called cryptanalysis. Keywords. Enigma, cryptanalysis, cypher, Caesar, Vigen`ere,Rejewski, Zygalski, Bomba, Bombe 1 Cipher not Code A code is a mapping from some meaningful unit (word, sentence, phrase) into something else (usually a shorter group of symbols). A code requires a codebook, it is simply a list of these mappings. For example we could make up a code where the word Apple is written as 67, historical example of this is \Zimmermann Telegram Code" for more details refer [7]. Ciphers do not involve meaning. Instead they are mechanical operations (known as algorithms) which are performed on the individual or small chunks of letters. A code is stored as a mapping in a codebook, while ciphers transform individual symbols according to an algorithm. It was definitively stated in 1883 by the Dutch linguist Auguste Kerckhoffs von Nieuwenhof in his book La Cryptographie militaire: Kerckhoffs' Principle: The security of a cryptosystem must not depend on keeping secret the crypto-algorithm. The security depends only on keeping secret the key.