Cryptanalysis of the Enigma by the letters on the top row of the Enigma keyboard. So, "continuation of message sent at 2330" was represented as "FORTYWEEPYYWEEPY". "Cribs" were fundamental to the British approach to solving Enigma keys, but guessing the plaintext for a message was a highly skilled business. So in 1940 Stuart Milner-Barry set up a special "Crib Room" in Hut 8. Foremost amongst the knowledge needed for identifying cribs was the text of previous decrypts. Bletchley Park maintained detailed indexes of message preambles, of every person, of every ship, of every unit, of every weapon, of every technical term and of repeated
Cryptanalysis of the Enigma current on the way out to the lamp panel. To decipher German military Enigma messages, the following information would need to be known. Logical structure of the machine (unchanging) Internal settings (usually changed less frequently than external settings) External settings (usually changed more frequently than internal settings) Discovering the logical structure of the machine may be called "breaking" it, a one-off process except when changes or additions were made to the machines. Finding the internal and external settings for one or more messages may be called "solving" - although breaking is often used for this process as well. The various