py-enigma 0.1

Description:

pyenigma 0.1

A historically accurate Enigma Machine library written in Python 3

Author:
Brian Neal <[email protected]>

Version:
0.1

Date:
June 5, 2012

Home Page:
https://bitbucket.org/bgneal/enigma/

License:
MIT License (see LICENSE.txt)

Documentation:
http://py-enigma.readthedocs.org/

Support:
https://bitbucket.org/bgneal/enigma/issues




Overview
Py-Enigma is a Python 3 library for simulating the Enigma machines used
by the German armed forces (Wehrmacht) during World War 2. Py-Enigma makes it
possible to both encrypt and decrypt messages that can be sent to, or received
from, actual Enigma machines used by the German army (Heer), air force
(Luftwaffe), and navy (Kriegsmarine).
It is my hope that library will be useful to Enigma enthusiasts, historians, and
students interested in cryptography.
Py-Enigma strives to be Pythonic, easy to use, comes with unit tests, and
documentation.


Scope
The current scope of Py-Enigma is to simulate Wehrmacht Enigma machines.
Simulation of other Enigmas, such as the various commercial, railroad, foreign,
and Abwher (Military Intelligence) models may come later if there is enough
interest and data available.
Currently, Py-Enigma can simulate the 3 and 4 rotor Enigma machines used by the
German army, navy, and air force.


Quick Example
This example shows how the library can be used to decode a message using the
procedure employed by the German army:
from enigma.machine import EnigmaMachine

# setup machine according to specs from a daily key sheet:

machine = EnigmaMachine.from_key_sheet(
rotors='II IV V',
reflector='B',
ring_settings=[1, 20, 11],
plugboard_settings='AV BS CG DL FU HZ IN KM OW RX')

# set machine initial starting position
machine.set_display('WXC')

# decrypt the message key
msg_key = machine.process_text('KCH')

# decrypt the cipher text with the unencrypted message key
machine.set_display(msg_key)

ciphertext = 'NIBLFMYMLLUFWCASCSSNVHAZ'
plaintext = machine.process_text(ciphertext)

print(plaintext)
This program prints:
THEXRUSSIANSXAREXCOMINGX
Py-Enigma also includes a command-line application for processing messages.
Assuming you have a proper key file that contains the same initial settings as
the code above, the above example can be performed on the command-line:
$ pyenigma.py --key-file=keys.txt --start=WXC --text='KCH'
BLA
$ pyenigma.py --key-file=keys.txt --start=BLA --text='NIBLFMYMLLUFWCASCSSNVHAZ'
THEXRUSSIANSXAREXCOMINGX
The format of the key file can be found in the documentation.


Requirements
Py-Enigma is written in Python, specifically Python 3.2. It has no other
requirements or dependencies.


Installation
Py-Enigma is available on the Python Package Index (PyPI). You can install it
using pip:
$ pip install py-enigma # install
$ pip install --upgrade py-enigma # upgrade
You may also download a tarball or .zip file of the latest code using the “get
source” link on the Py-Enigma Bitbucket page. Alternatively if you use
Mercurial, you can clone the repository with the following command:
$ hg clone https://bitbucket.org/bgneal/enigma
If you did not use pip, you can install with this command:
$ python setup.py install


Documentation
The latest documentation is available at Read the Docs. There you can browse the
documentation online, or
download it in a variety of formats.
Sources for the documentation are also included in Sphinx format. If you
install Sphinx you can generate the documentation in several output formats.


Support
Support is provided at the issue tracker at the Py-Enigma Bitbucket page.
If you have general questions or comments, please feel free to email me (address
at the top of this file).
And please, if you use Py-Enigma for anything, even if it is just learning,
please let me know!


Acknowledgements & References
This software would not have been possible without the thorough and detailed
descriptions of the Enigma machine on Dirk Rijmenants’ incredible Cipher
Machines and Cryptology website. In particular, his Technical Details of the
Enigma Machine page was a gold mine of information.
Dirk has also written an Enigma simulator in Visual Basic. Although I did not
look at his source code, I did use his simulator to check the operation of
Py-Enigma.
I would also like to recommend the photos and video at Dr. Thomas B. Perera’s
Enigma Museum.
Another good website is The Enigma and the Bombe by Graham Ellsbury.
A nice video which shows the basic components and operation of the Enigma
Machine is on YouTube: Nadia Baker & Enigma demo.