Created by: Brandon Ingli

$enigma

$enigma [message] [r1] [r1o] [r2] [r2o] [r3] [r3o] [ref]

Encode or decode a message using Spike’s enigma machine.

Parameter	Details	Default
message	String to encode/decode	(Required; no default)
r1	Name of rotor to use in rightmost position	I
r1o	Starting offset for rightmost rotor, 0<=x<=25	0
r2	Name of rotor to use in center position	II
r2o	Starting offset for center rotor, 0<=x<=25	0
r3	Name of rotor to use in leftmost position	III
r3o	Starting offset for leftmost rotor, 0<=x<=25	0
ref	Name of reflector to use	B

Rotor Names: I, II, III, IV, V
Reflector Names: A, B, C

Note: This enigma may have the rotors in reverse order when compared to other enigma machines, including the Enigma I it emulates.

The History

The Enigma Machine was a device used by the German military in World War II to encode messages. This enigma machine emulates an Enigma I without a plugboard.

Messages are encoded by being sent as electrical signals through a series of rotors. There were 5 of these available, and could be installed into one of three slots in the machine. Each rotor could be in any of 26 positions at a given time. Inside, the rotors are wired to match one input with one output on the other end. When a key is pressed, the electrical signal representing that letter travels through the rotors, is reflected at the end, and sent back through the rotors to light a corresponding light. The reflector ensures that a letter never encodes to itself.

What makes the cipher tricky is that fact that these rotors rotate. The rightmost rotor rotates once every time you press a key. Once that rotates fully, the middle rotor rotates once as well. When the middle rotor has completed a full rotation, the leftmost rotor also rotates.

For more information, please see the Wikipedia Entry for the Enigma machine.