sdes 0.1.3

Simplified Data Encryption Standard (S-DES) Implementation

S-DES (Simplified Data Encryption Standard)

S-DES (Simplified Data Encryption Standard) is a lightweight block cipher that operates on 8-bit blocks. This package implements the encryption and decryption functionality of S-DES using a 10-bit key.

Installation

To install the package, you can use the following pip command:

pip install sdes
pip install bitarray

If you are developing locally, you can install the package in editable mode:

pip install -e .

Usage

You can use this package to perform encryption and decryption using the Simplified Data Encryption Standard (S-DES) algorithm.

Example Usage

from sdes import encrypt, decrypt, generate_keys
import bitarray

# Example 10-bit key (must be 10-bits long)
key = bitarray.bitarray('1010000010')

# Example 8-bit plaintext (must be 8-bits long)
plaintext = bitarray.bitarray('11010011')

# Generate subkeys
key1, key2 = generate_keys(key)

# Encrypt the plaintext
ciphertext = encrypt(plaintext, key1, key2)
print("Encrypted:", ciphertext)

# Decrypt the ciphertext
decrypted_text = decrypt(ciphertext, key1, key2)
print("Decrypted:", decrypted_text)

Functions

• generate_keys(key)
  Generates two 8-bit subkeys (key1 and key2) from the provided 10-bit key.

  Parameters:

  • key (bitarray): The 10-bit key.

  Returns:

  • key1 (bitarray): First subkey.
  • key2 (bitarray): Second subkey.

• encrypt(plaintext, key1, key2)
  Encrypts the 8-bit plaintext using the two subkeys (key1 and key2) according to the S-DES algorithm.

  Parameters:

  • plaintext (bitarray): The 8-bit plaintext to encrypt.
  • key1 (bitarray): First subkey.
  • key2 (bitarray): Second subkey.

  Returns:

  • ciphertext (bitarray): The encrypted 8-bit ciphertext.

• decrypt(ciphertext, key1, key2)
  Decrypts the 8-bit ciphertext using the two subkeys (key1 and key2) according to the S-DES algorithm.

  Parameters:

  • ciphertext (bitarray): The 8-bit ciphertext to decrypt.
  • key1 (bitarray): First subkey.
  • key2 (bitarray): Second subkey.

  Returns:

  • decrypted_text (bitarray): The decrypted 8-bit plaintext.

Requirements

This package requires the following libraries:

• bitarray: A Python module for efficiently working with bit arrays.
• numpy: A package for numerical computations (optional for your case but can be useful for optimization).

You can install the dependencies using:

pip install bitarray numpy

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Feel free to open issues and submit pull requests. Contributions are welcome!