Cypher Tool

A Java-based command-line tool for encrypting and decrypting messages using ROT13, Atbash, and a custom cipher.

Features

• Encryption/Decryption Operations: Supports ROT13, Atbash, and Caesar cipher.
• Interactive CLI: User-friendly command-line interface for input and output.
• Input Validation: Ensures valid input for operations, ciphers, and messages.
• Error Handling: Provides clear feedback for invalid inputs and handles edge cases.

Supported Ciphers

1. ROT13: Rotates each letter by 13 places in the alphabet.
2. Atbash: Maps each letter to its reverse in the alphabet (A ↔ Z, B ↔ Y, etc.).
3. Caesar Cipher: It is a type of substitution cipher where each letter in the plaintext is shifted by a fixed number of positions down or up the alphabet.

Contributing

Contributions are welcome! Please follow these steps:

• Fork the repository.

• Create a new branch for your feature or bugfix (e.g. feature/rot-13)

• Submit a pull request with a detailed description of your changes.

Running

Compile the Java files:

javac -d build Main.java

Run the project:

java -cp ./build Main