Substitution Cipher

A cross-platform C++ console application that implements a simple substitution cipher for text encryption and decryption.

🚀 Quick Start

One-Click Setup

Choose the script for your operating system:

Platform	Script	Command
macOS	docs/setup/setup-macos.sh	chmod +x docs/setup/setup-macos.sh && ./docs/setup/setup-macos.sh
Linux	docs/setup/setup-linux.sh	chmod +x docs/setup/setup-linux.sh && ./docs/setup/setup-linux.sh
Windows (CMD)	docs/setup/setup-windows.bat	Double-click or run docs\setup\setup-windows.bat
Windows (PowerShell)	docs/setup/setup-windows.ps1	Set-ExecutionPolicy Bypass -Scope Process; .\docs\setup\setup-windows.ps1

The setup scripts will:

1. ✅ Install required dependencies (CMake, compiler)
2. ✅ Configure Git for cross-platform development
3. ✅ Build the project
4. ✅ Optionally run the application

Manual Build

# Clone the repository
git clone https://github.com/The-Sequence/Substitution-Cipher.git
cd Substitution-Cipher

# Create build directory
mkdir build && cd build

# Configure and build
cmake .. -DCMAKE_BUILD_TYPE=Release
cmake --build .

# Run (path varies by platform)
./bin/SubstitutionCipher          # macOS/Linux
.\bin\Release\SubstitutionCipher.exe  # Windows

✨ Features

• Encrypt text using a 52-character substitution key
• Decrypt text back to original plaintext
• View current key being used for encryption
• Generate new random keys using Fisher-Yates shuffle algorithm
• Set custom encryption keys for specific use cases
• Chat history logging - saves encryption sessions to file

📖 How It Works

The substitution cipher replaces each letter in the alphabet with a corresponding letter from a key:

Original:  abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ
Key:       xjqnmhklcbydogfretiupaswvzXJQNMHKLCBYDOGFRETIUPASWVZ

Example:   "Hello" → "Kmyyo"

📁 Project Structure

Substitution-Cipher/
├── main.cpp              # Application entry point
├── choiceLogic.cpp       # Encryption/decryption logic
├── ChoiceLogic.h         # Header for choice logic
├── InputValidation.cpp   # User input handling
├── InputValidation.h     # Header for input validation
├── CMakeLists.txt        # CMake build configuration
├── README.md             # This file
├── LICENSE.txt           # MIT License
├── docs/
│   ├── guides/           # Documentation guides
│   │   ├── BUILD.md      # Detailed build instructions
│   │   ├── WINDOWS_BUILD_GUIDE.md
│   │   └── ...
│   └── setup/            # One-click setup scripts
│       ├── setup-macos.sh
│       ├── setup-linux.sh
│       ├── setup-windows.bat
│       └── setup-windows.ps1
└── .github/
    └── workflows/        # CI/CD configuration

🛠️ Requirements

• CMake 3.24 or higher
• C++17 compatible compiler:
  • GCC 7+ (Linux)
  • Clang 5+ / Xcode Command Line Tools (macOS)
  • MSVC 2019+ / Visual Studio (Windows)

📚 Documentation

Document	Description
BUILD.md	Comprehensive build instructions for all platforms
WINDOWS_BUILD_GUIDE.md	Windows-specific setup guide
WINDOWS_QUICK_REFERENCE.md	Quick reference for Windows developers
RESTRUCTURING_SUMMARY.md	Recent project restructuring and organization changes

🤝 Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add 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.txt file for details.

🙏 Acknowledgments

• First proper GitHub project! Created on August 9, 2023 (Wednesday)
• Uses the classic substitution cipher technique for educational purposes

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Last updated: December 2024