Feistel Cipher

The Feistel Cipher package can be used to implement a Feistel Cipher using either inbuilt or custom functions for encyrpting and decrypting integers.

Current Version: 0.2.0

Requires: Python 3.5+

Inspiration

The creation of the package is both inspired by and based on the explanation given Dr. Mike Pound on the Computerphile YouTube channel in the video titled Feistel Cipher - Computerphile.

Installation

You can install the Feistel Cipher package from PyPI

pip install feistelcipher

Usage

Import the necessary classes

import feistelcipher.FeistelCipher as fc
import feistelcipher.CryptFunctions as cfs
import feistelcipher.StandardCryptFunctions as scf

Create a CryptFunctions object

funcList = cfs.CryptFunctions()

Add functions and associated keys to the CryptFunctions object

funcList.addFunc(scf.strLength)
funcList.addFunc(scf.quotient, [7])
funcList.addFunc(scf.power, [3])
funcList.addFunc(scf.truncate, [5])
funcList.addFunc(scf.scaledDistance, [1, 2, 3, 4])

Create a FeistelCipher object using the CryptFunctions object

cipher = fc.FeistelCipher(funcList)

Encryption

enc = cipher.encrypt(1_234_567)
print(repr(enc))

Output

>>> EncryptedObject(437201434, 43067, 4)

Decryption

dec = cipher.decrypt(enc)
print(dec)

Output

>>> 1234567

Advanced Usage and Explanation

For detailed explanation and usage of this package with custom functions, kindly refer to Examples.ipynb in the GitHub repo.

Upcoming improvements

• Support for Keyword arguments
• Encrypting/Decrypting iterables of integers
• Support for easily saving the FeistelCipher object to a pickled or binary file
• Improved Documentation

Thank You

If you liked this package or found it useful, consider starring the associated GitHub repository.

Created by - Mayur Kr. Garg