libciphers

A Python library providing implementations of classical cipher algorithms for cryptographic puzzles, CTF challenges, and educational purposes.

Install

pip install libciphers

Usage

from libciphers import caesar_encrypt, caesar_decrypt, vigenere_encrypt, vigenere_decrypt

# Caesar cipher
plaintext = "HELLO"
encrypted = caesar_encrypt(plaintext, 5)
decrypted = caesar_decrypt(encrypted, 5)
print(f"Caesar: {encrypted} -> {decrypted}")  # MJQQT -> HELLO

# Vigenère cipher
encrypted = vigenere_encrypt("HELLO", "KEY")
decrypted = vigenere_decrypt(encrypted, "KEY")
print(f"Vigenère: {encrypted} -> {decrypted}")  # RIJVQ -> HELLO

Supported Ciphers

Shift Ciphers

• Caesar (with brute force)
• ROT13, ROT-N
• Atbash
• Affine

Polyalphabetic Ciphers

• Vigenère
• Beaufort
• Variant Beaufort
• Autokey
• Running Key
• Porta
• Gronsfeld
• Quagmire variants

Transposition Ciphers

• Columnar
• Rail Fence
• Scytale
• Route
• Zigzag

Digraph Ciphers

• Playfair
• Four-Square
• Three-Square

Fractionated Ciphers

• Bifid
• Trifid

Other Ciphers

• Hill (2x2)
• Polybius Square
• Bazeries
• XOR
• Enigma (3-rotor)

Statistical Analysis

• Index of Coincidence
• Chi-squared
• N-gram scoring
• Kasiski examination

Development

git clone https://github.com/daedalus/libciphers.git
cd libciphers
pip install -e ".[test]"

# run tests
pytest

# format
ruff format src/ tests/

# lint
ruff check src/ tests/

# type check
mypy src/