Cryptography Web Application

A comprehensive web application that implements various cryptographic algorithms including AES, DES, Caesar, Vigenere, Vernam, and Transposition ciphers. The application provides both text and file encryption/decryption capabilities through a user-friendly interface.

Features

Encryption Algorithms

• AES (Advanced Encryption Standard): 128-bit encryption with ECB mode
• DES (Data Encryption Standard): TripleDES implementation
• Caesar Cipher: Classic shift cipher with customizable shift value
• Vigenere Cipher: Poly-alphabetic substitution cipher
• Vernam Cipher: XOR-based encryption with key length matching file size
• Transposition Cipher: Columnar transposition with keyword-based encryption

Core Functionality

• Text encryption/decryption
• File encryption/decryption
• Support for various file types
• Automatic key generation for Vernam cipher
• Swagger API documentation
• RESTful API backend
• Modern React-based frontend
• Responsive and intuitive user interface

Prerequisites

• Node.js (v14 or higher)
• npm (v6 or higher)
• Modern web browser (Chrome, Firefox, Safari, or Edge)

Setup Instructions

Backend Setup

1. Navigate to the backend directory:

cd backend

2. Install dependencies:

npm install

3. Create a .env file in the backend directory with the following content:

PORT=5000

4. Start the backend server:

node server.js

The backend will be available at http://localhost:5000

Frontend Setup

1. Navigate to the frontend directory:

cd frontend

2. Install dependencies:

npm install

3. Start the development server:

npm start

The frontend will be available at http://localhost:3000

API Documentation

Once the backend is running, you can access the Swagger API documentation at: http://localhost:5000/api-docs

Security Specifications

Key Requirements

• AES: 16-character key
• DES: 24-character key
• Caesar: Numeric shift value
• Vigenere: Alphabetic key
• Vernam: Key length must match file size
• Transposition: Keyword with at least 2 unique characters

File Handling

• Maximum file size: 100MB
• Supports various file types (text, binary, etc.)
• Secure file upload and download
• Input validation on both frontend and backend

Testing

Backend Testing

1. Navigate to the backend directory
2. Run tests:

npm test

Frontend Testing

1. Navigate to the frontend directory
2. Run tests:

npm test

Project Structure

CryptographyWebApp/
├── backend/
│   ├── server.js          # Main server file
│   ├── swagger.js         # API documentation
│   ├── tests/             # Test files
│   └── package.json       # Backend dependencies
├── frontend/
│   ├── src/              # React source code
│   ├── public/           # Static files
│   └── package.json      # Frontend dependencies
└── README.md             # Project documentation

Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Built with Node.js and Express for the backend
• React for the frontend
• CryptoJS for cryptographic operations
• Swagger for API documentation