Vigenère Cipher Tools

This program implements the Vigenère cipher, a method of encrypting and decrypting texts using a repeating key.

Requirements

This program requires Python 3.

Usage

To run the program, use the following command:

python cipher_tools.py [operation] [options]

Options

• operation: The operation to perform. Must be one of encode, decode, or reversekey.
• --alphabet, -a: The alphabet to use. Required for all operations.
• --key, -k: The key for the cipher. Required for encode and decode operations.
• --plaintext, -p: The plaintext. Required for encode and reversekey operations.
• --ciphertext, -c: The ciphertext for the cipher. Required for decode and reversekey operations.

Examples

To encode a message using the Vigenère cipher:

python cipher_tools.py encode -a ABCDEFGHIJKLMNOPQRSTUVWXYZ -k HELLO -p HELLO

To decode a message using the Vigenère cipher:

python cipher_tools.py decode -a ABCDEFGHIJKLMNOPQRSTUVWXYZ -k HELLO -c IFMMP

To find the key for a Vigenère cipher using the plaintext and ciphertext:

python cipher_tools.py reversekey -a ABCDEFGHIJKLMNOPQRSTUVWXYZ -p HELLO -c IFMMP

Table Generator

This repository also includes a tool for generating a lookup table for ciphers. To use the tool, run the following command:

python3 table_generator.py [ALPHABET] [IMAGE]

Options

• ALPHABET: The alphabet to generate a table for.
• IMAGE: A boolean value indicating whether or not to generate an image. Optional.

Examples

To generate a lookup table for the alphabet "ABCDEFGHIJKLMNOPQRSTUVWXYZ":

python3 table_generator.py ABCDEFGHIJKLMNOPQRSTUVWXYZ

To generate a lookup table for the alphabet "ABCDEFGHIJKLMNOPQRSTUVWXYZ" and an image:

python3 table_generator.py ABCDEFGHIJKLMNOPQRSTUVWXYZ True