Vigenère and Vernam Cipher Encryption/Decryption Tool

This project is a Python implementation of two classical cryptography techniques: the Vigenère Cipher and the Vernam Cipher. It allows users to encrypt and decrypt messages using either cipher method through a simple command-line interface.

Features

Vigenère Cipher:
- Encrypt plaintext using a keyword.
- Decrypt ciphertext using the same keyword.
Vernam Cipher:
- Encrypt plaintext using a keyword of the same length.
- Decrypt ciphertext using the same keyword.

Prerequisites

Python 3.x

How to Use

Clone the Repository:

git clone https://github.com/thesaajii/Cryptography.git
cd cipher-tool

Run the Script:
```
python3 cipher.py
```
Choose the Cipher Method:
- Select 1 for Vigenère Cipher.
- Select 2 for Vernam Cipher.
Choose the Operation:
- Select 1 for Encryption.
- Select 2 for Decryption.
Input the Required Data:
- For Vigenère Cipher: Input the plaintext/ciphertext and keyword.
- For Vernam Cipher: Input the plaintext/ciphertext and a keyword of the same length.
View the Result:
- The program will output the encrypted or decrypted text.

Example

Vigenère Cipher

Encrypting:
- Plaintext: HELLO
- Keyword: KEY
- Ciphertext: RIJVS
Decrypting:
- Ciphertext: RIJVS
- Keyword: KEY
- Plaintext: HELLO

Vernam Cipher

Encrypting:
- Plaintext: HELLO
- Keyword: XMCKL
- Ciphertext: EQNVZ
Decrypting:
- Ciphertext: EQNVZ
- Keyword: XMCKL
- Plaintext: HELLO

Notes

The Vernam Cipher requires the keyword to be of the same length as the plaintext or ciphertext.
The script only handles uppercase English letters (A-Z). Ensure your inputs are in uppercase.

Contributing

Feel free to fork this repository, submit issues, and make pull requests. Contributions are always welcome!