🔐 SafeBox - File Encryptor/Decryptor

A lightweight command-line file encryption tool built with modern C++

Features • Installation • Usage • How It Works • Learning Journey

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📖 About The Project

SafeBox is a command-line file encryption/decryption tool that uses the XOR cipher algorithm to secure your files. This project was built as part of my journey to master C++ programming, focusing on file I/O operations, binary data manipulation, and secure coding practices.

⚠️ Disclaimer: This tool is built for educational purposes. For production-grade security, consider using established encryption libraries like OpenSSL or libsodium.

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✨ Features

Feature	Description
🔒 File Encryption	Encrypt any file type using XOR cipher with a custom key
🔓 File Decryption	Decrypt encrypted files using the same key
🗑️ Secure Shred	Optionally delete the original file after encryption
📁 Binary Mode	Works with all file types (text, images, documents, etc.)
💻 CLI Interface	Simple and intuitive command-line interface
🎯 Cross-Platform	Works on Windows, Linux, and macOS

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🚀 Installation

Prerequisites

• C++ Compiler (GCC, Clang, or MSVC)
• C++11 or later

Build Instructions

# Clone the repository
git clone https://github.com/yourusername/SafeBox.git
cd SafeBox

# Compile using g++
g++ -o safebox main.cpp Encryptor.cpp -std=c++11

# Or using MSVC (Windows)
cl /EHsc main.cpp Encryptor.cpp /Fe:safebox.exe

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📋 Usage

Basic Syntax

./safebox <mode> <filename> <key> [options]

Modes

Mode	Description
-e	Encrypt the file
-d	Decrypt the file

Options

Option	Description
--shred	Delete the original file after encryption (with confirmation)

Examples

# 🔐 Encrypt a file
./safebox -e secret.txt MySecretKey123

# 🔓 Decrypt a file
./safebox -d secret.txt.enc MySecretKey123

# 🗑️ Encrypt and shred original file
./safebox -e confidential.pdf SuperSecretKey --shred

Output

==========================================================
                  SAFEBOX FILE ENCRYPTOR          
==========================================================

Usage: \.safebox <mode> <filename> <key> [options]
Modes: 
  -e : Encrypt the file
  -d : Decrypt the file
Options: 
  --shred : Delete the original file after encryption
Example: 
  .\safebox -e myfile.txt K
Remember your key! Without it, decryption is not possible.

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🔧 How It Works

XOR Cipher Algorithm

SafeBox uses the XOR (Exclusive OR) cipher, a symmetric encryption technique:

Encrypted = Original XOR Key
Original = Encrypted XOR Key

Encryption Process

graph LR
    A[📄 Input File] --> B[Read Byte]
    B --> C[XOR with Key]
    C --> D[Write to Output]
    D --> E{More Bytes?}
    E -->|Yes| B
    E -->|No| F[🔐 Encrypted File]

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Key Features of Implementation

1. Binary File Handling: Uses ios::binary flag for raw byte operations
2. Cyclic Key Application: Key repeats cyclically for files larger than key length
3. Memory Efficient: Processes file byte-by-byte, suitable for large files
4. Error Handling: Comprehensive validation for file operations and user input

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📁 Project Structure

SafeBox/
├── 📄 main.cpp           # Entry point and CLI handling
├── 📄 Encryptor.cpp      # Core encryption/decryption logic
├── 📄 Encryptor.h        # Encryptor class header
├── 📄 README.md          # Project documentation
└── 🔒 test.txt.enc       # Sample encrypted file

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🎓 Learning Journey

Concepts Mastered

Concept	Description
📚 File I/O	Binary file reading/writing with ifstream and ofstream
🔤 String Manipulation	Substring extraction, string finding operations
🎛️ Command Line Args	Parsing argc and argv for CLI applications
🏗️ OOP Principles	Class design with separate header and implementation files
⚠️ Error Handling	Input validation and graceful error messages
🔢 Bitwise Operations	XOR operation for encryption
📦 Modular Code	Separation of concerns with reusable components

Skills Developed

• ✅ Working with binary data in C++
• ✅ Building command-line applications
• ✅ Understanding symmetric encryption basics
• ✅ File system operations (read, write, delete)
• ✅ Memory-efficient stream processing
• ✅ Clean code organization and documentation

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🔮 Future Improvements

• 🔑 Stronger Encryption: Implement AES-256 encryption using OpenSSL
• 🔒 Password Hashing: Add key derivation function (PBKDF2/Argon2)
• 📊 Progress Bar: Show encryption progress for large files
• 📁 Directory Support: Encrypt entire directories recursively
• 🗜️ Compression: Add file compression before encryption
• 🔐 Key File Support: Use key files instead of command-line keys
• 🧪 Unit Tests: Add comprehensive test suite
• 📝 Logging: Add detailed logging for debugging
• 🖥️ GUI Version: Create a graphical user interface
• 🔄 Parallel Processing: Multi-threaded encryption for faster processing

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⚠️ Security Considerations

Important: XOR cipher alone is NOT cryptographically secure for protecting sensitive data.

Known Limitations

1. Key Vulnerability: Key can be recovered through known-plaintext attacks
2. No Authentication: Doesn't verify file integrity
3. Key Repetition: Short keys create patterns in encrypted data

Recommendations for Production Use

• Use established libraries (OpenSSL, libsodium)
• Implement proper key derivation functions
• Add message authentication codes (MAC)
• Never hardcode keys in source code

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👤 Author

Utkarsh Gupta

[][(https://github.com/utkarshgupta-iitbhu)] [][(https://www.linkedin.com/in/utkarsh-gupta-iitbhu/)]

A passionate developer learning C++ and building cool projects!

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