Enigma

A Ruby implementation of the Enigma machine.

Installation

Add this line to your application's Gemfile:

gem 'enigma'

And then execute:

$ bundle

Or install it yourself as:

$ gem install enigma

Usage

Basic example:

# 1. Instantiate an Enigma machine:
enigma = Enigma::Enigma.new(
  rotors: [Enigma::RotorI.new, Enigma::RotorII.new, Enigma::RotorIII.new],
  reflector: Enigma::ReflectorB.new,
  rotations: 'AAA',
  rings: 'AAA',
  plugboard: %w(AB IR UX KP)
)

# 2. Encode / decode the message:
encoded_message = enigma.encode('AAAAA')

You can also set any parameter with reset:

enigma.reset(rotations: 'AAA', rings: 'AAA')

or through the accessors:

enigma.rotations = 'AAA'

Parameters:

• rotors

  An array of Rotor objects.

  Set from left to right.

  RotorI, II, III, IV and V are available.

• reflector

  A Reflector object.

  ReflectorB is the only one available.

• rotations

  A string of upcase A..Z chars. One for each rotor. (defaults to 'A')

  Sets the initial rotation of each rotor. (i.e. it's the message key code)

• rings

  A string of upcase A..Z chars. One for each rotor. (defaults to 'A')

  Or an array of 1..26 numbers. One for each rotor.

  Sets the ring position of each rotor.

• plugboard

  An array of upcase 2-char strings. One string for each connected letter pair. (defaults to all letters mapping to themselves)

  Sets the connections on the plugboard.

Todo

Test the encoding with real-world parameters and messages.

Add more Enigma models, rotors and reflectors.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release to create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

1. Fork it ( https://github.com/otagi/enigma/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request