The Enigma Machine: Mechanism and Use
The Enigma machine, first patented in 1919, was improved by the German Navy, Army, and Air Force
1926-1935. It was also used by the Abwehr, a German military intelligence organization, and other government agencies.
The Enigma was used solely to encipher and decipher messages. From the cipher operator's point of view, it consisted first of a keyboard of 26 letters in the standard format, however there are no numerals or punctuation. Behind this keyboard is a "lampboard" of 26 small circular windows, each bearing a letter in the same QWERT pattern, which would light up, one at a time, from bulbs underneath. Behind the "lampboard" is the scrambler unit. Each time the cipher clerk keyed a letter, the signal passes through the plugboard which switches the letter, for example from F to Z. Three rotors each change the output letter before a reflector sends the signal back through the machine. Finally the signal lights up a letter on the on the "lampboard". The cipher operator copies the lit letters and sends the encryption using morse code. Mathematically, the Enigma offers a variety of about 10,000,000,000,000,000 different keys. The reflector led to a flaw in the Enigma however. No letter would ever be encoded as itself. With that knowledge, it was possible to eliminate potential rotor positions.
1926-1935. It was also used by the Abwehr, a German military intelligence organization, and other government agencies.
The Enigma was used solely to encipher and decipher messages. From the cipher operator's point of view, it consisted first of a keyboard of 26 letters in the standard format, however there are no numerals or punctuation. Behind this keyboard is a "lampboard" of 26 small circular windows, each bearing a letter in the same QWERT pattern, which would light up, one at a time, from bulbs underneath. Behind the "lampboard" is the scrambler unit. Each time the cipher clerk keyed a letter, the signal passes through the plugboard which switches the letter, for example from F to Z. Three rotors each change the output letter before a reflector sends the signal back through the machine. Finally the signal lights up a letter on the on the "lampboard". The cipher operator copies the lit letters and sends the encryption using morse code. Mathematically, the Enigma offers a variety of about 10,000,000,000,000,000 different keys. The reflector led to a flaw in the Enigma however. No letter would ever be encoded as itself. With that knowledge, it was possible to eliminate potential rotor positions.