Enigma Machine

The Enigma machine is an electro-mechanical encryption device used during World War II. It enciphers messages using a series of rotors and a reflector, which allowed for secure communication among the German military.

How it works:

Rotor class: Represents a single rotor in the Enigma machine. It takes a wiring parameter that defines the substitution wiring, a notch position for turnover, a ring_setting to configure the initial position of the ring, and an offset to set the initial position of the rotor.

Reflector class: Represents the reflector in the Enigma machine. It takes a wiring parameter that defines the substitution wiring for the reflector.

EnigmaMachine class: Represents the entire Enigma machine. It takes three parameters: rotor_settings, reflector_wiring, and plugboard_connections. rotor_settings is a list of tuples, each containing the wiring, notch, ring_setting, and offset for each rotor. reflector_wiring defines the substitution wiring for the reflector, and plugboard_connections is a list of plugboard pairs.

substitute_plugboard(char): This method substitutes characters based on the plugboard connections defined in plugboard_connections.

encrypt(message): This method takes a message as input and encrypts it using the Enigma machine. It performs the following steps:

• Substitutes characters based on plugboard connections.
• Passes the character through each rotor from left to right using the substitute_forward method.
• Reflects the character using the reflector.
• Passes the character through each rotor in reverse order using the substitute_backward method.
• Substitutes characters based on plugboard connections again.
• Rotates the first rotor, and if a notch is reached, rotates the next rotor.

Usage:

To use the Enigma machine, create an instance of the EnigmaMachine class with appropriate rotor settings, reflector wiring, and plugboard connections. Then, call the encrypt(message) method with the message you want to encrypt. The encrypted message will be returned.

Example usage:

rotor_settings = [
    ("EKMFLGDQVZNTOWYHXUSPAIBRCJ", "Q", 0, 0),
    ("AJDKSIRUXBLHWTMCQGZNPYFVOE", "E", 0, 0),
    ("BDFHJLCPRTXVZNYEIWGAKMUSQO", "V", 0, 0),
]
reflector_wiring = "YRUHQSLDPXNGOKMIEBFZCWVJAT"
plugboard_connections = [("A", "M"), ("G", "L"), ("P", "R"), ("S", "T")]

enigma = EnigmaMachine(rotor_settings, reflector_wiring, plugboard_connections)
message = "HELLO"
encrypted_message = enigma.encrypt(message)
print("Original message:", message)
print("Encrypted message:", encrypted_message) 

Note: This implementation is a simplified version of the historical Enigma machine, mainly for educational purposes, and may not include all the complexities and features of the original machine used during World War II.