ddes-dua-crypto 0.1.1

Dynamic Data Encryption Standard (D-DES) with a single dynamic S-box.

D-DES (Dynamic Data Encryption Standard)

⚠️ Security Disclaimer: This is an experimental cryptographic tool for research and educational purposes. It is not intended for securing sensitive production data.

D-DES is a custom implementation of the classic DES (Data Encryption Standard) block cipher, modified to feature a Dynamic S-Box.

Requirements

• Python 3.8+: This library leverages Python type hinting and bit-manipulation features. Ensure you are running Python 3.8 or higher.

Features

• Standard 64-bit block size and 56-bit effective key.
• 16 Feistel rounds with standard permutation tables (IP, IP-1, E, P, PC-1, PC-2).
• Dynamic S-Box: Replaces the 8 static S-boxes with a single, dynamically generated $6 \times 4$ S-box completely seeded by the encryption key.
• CBC Mode Support: Prevents repeating data blocks by utilizing an Initialization Vector (IV).
• PKCS#7 Padding: Safely encrypts and decrypts files of any arbitrary size.
• CLI Utility: Built-in command line interface to seamlessly encrypt/decrypt any file on your computer.
• Operational Logger: Automatically and securely logs operation metadata to a logs.json file without leaking secrets or plaintext.

Installation

You can install the package directly from PyPI. In your terminal, run:

pip install ddes-dua-crypto

CLI Usage

The package installs a globally available ddes-cli tool.

To encrypt a file (CBC mode):

ddes-cli encrypt -k "8bytekey" -m CBC --iv "8byte_iv" -i plaintext.txt -o encrypted.bin

To decrypt a file:

ddes-cli decrypt -k "8bytekey" -m CBC --iv "8byte_iv" -i encrypted.bin -o decrypted.txt

Python API Usage

You can also use the cipher directly inside your own Python projects.

from ddes import DDESCipher

# 8-byte key and IV
key = b'8bytekey'
iv = b'8byte_iv'

# Initialize in CBC mode
cipher = DDESCipher(key, mode='CBC', iv=iv)

# Encrypt
plaintext = b'Hello World! This is D-DES.'
ciphertext = cipher.encrypt(plaintext)
print(f"Ciphertext (Hex): {ciphertext.hex()}")

# Decrypt
decrypted = cipher.decrypt(ciphertext)
print(f"Decrypted: {decrypted.decode('utf-8')}")

Operational Logger

All CLI encryption and decryption commands automatically append an audit trail to logs.json. The logger securely stores the timestamp, operation type, mode, and success status. It never stores keys or file contents.

Example Audit Log (logs.json):

[
    {
        "timestamp": "2026-05-08T19:02:15.123456",
        "operation": "Encrypt",
        "mode": "CBC",
        "status": "Success"
    }
]