Enigma Machine

The EnigmaMachine allows to create a python instance to cipher texts. It has to be composed by three parts: the PlugBoard, the Rotor and the Reflector. The settings of all three parts are defined as the machine's configuration.

The EnigmaMachine class can be imported directly from the enigma_cipher package:

from enigma_cipher import EnigmaMachine

EnigmaMachine(plugboard, rotors, reflector, reset_after_ciphering=True)

Constructor of the EnigmaMachine cipher. All specified components (plugboard, rotors and reflector) but have defined the same include_digits choice.

Parameters

• plugboard PlugBoard:
  Component of the PlugBoard. It specifies the mapping among all the keys at the input/output level.
• rotors Sequence of Rotor:
  Initialized Rotor instances in a sequence. While the historic enigma machine contained only three rotors, the EnigmaMachine class can work with as many or few as desired.
• reflector Reflector:
  Component of the Reflector.
• reset_after_ciphering bool (default = True):
  Flag that controls if the machine should reset to the initial configuration after ciphering a text.

EnigmaMachine.cipher_text(text)

Proceeds to cipher a given text. Ciphering will decode an encoded text if the machine has the same configuration as the initial machine that encoded the text.

Parameters

• text str:
  Message to cipher (encode or decode) with the current configuration.

Returns

• str:
  The ciphered text.

EnigmaMachine.export_configuration_to_json_file(output_path, force=False)

Export the machine configuration to a '.json' file.

Parameters

• output_path str:
  Path to the file to contain the configuration. Values as "path/to/file" will create a file "path/to/file.json".
• force bool (default = False):
  If True, allows overwriting existing output files. Otherwise, raises an error if the file already exists.

Class methods

EnigmaMachine.random_configuration(nof_rotors=None, reset_after_ciphering=True, include_digits=False)

Initializes the machine and all its components with a random configuration.

Parameters

• nof_rotors int, optional:
  Number of rotors that compose the machine. If not specified, a randon number of them between 2 and 10 will be configured.
• reset_after_ciphering bool, default = True:
  Flag that controls if the machine should reset to the initial configuration after ciphering a text.
• include_digits bool, default = False:
  If True, the EnigmaMachine will include the digits to be ciphered. As default, only letters are to be ciphered.

Returns

• EnigmaMachine:
  The instance initialized to a totally random configuration for all the elements.

EnigmaMachine.from_configuration(configuration, reset_after_ciphering=True)

Initializes the machine from a specified configuration.

Parameters

• configuration dict:
  Mapping containing the machine configuration. It must be defined as the one returned in EnigmaMachine.initial_config.
• reset_after_ciphering bool (default = True):
  Flag that controls if the machine should reset to the initial configuration after ciphering a text.

Returns

• EnigmaMachine:
  The instance initialized to the specified configuration.

EnigmaMachine.from_configuration_file(input_path, reset_after_ciphering=True)

Initializes the machine from a .json configuration file. Configuration files from previous released versions are supported.

Parameters

• input_path str:
  Path to the .json file containing the configuration.
• reset_after_ciphering bool (default = True):
  Flag that controls if the machine should reset to the initial configuration after ciphering a text.

Returns

• EnigmaMachine:
  The instance initialized to the specified configuration within the file.

Properties

EnigmaMachine.initial_configuration

Returns

• dict:
  Initial configuration as a dictionary with the keys 'plugboard', 'rotors', 'reflector' and 'alphanumeric'.