HuffSecure: Encrypted File Compressor

HuffSecure is a high-performance command-line file compression tool built in C++. It implements the Huffman Coding algorithm for lossless data compression and adds a layer of security via XOR-based header obfuscation, ensuring that compressed archives remain inaccessible without the correct password.

Key Features

• Lossless Compression: Reduces file size efficiently using frequency-based Huffman binary trees.
• Secure Archives: Protects the critical decoding header using XOR encryption logic. Without the password, the Huffman tree cannot be reconstructed, rendering the payload unreadable.
• Memory Safe: Implements strict memory management to ensure all encoding trees and buffers are deallocated post-process (0 bytes leaked).
• Custom File Format: Writes a serialized binary header containing the frequency table and encryption metadata.

Technical Implementation

The Compression Pipeline

1. Frequency Analysis: Scans the input file to build a frequency map of all bytes.
2. Tree Construction: Uses a Priority Queue to build a Huffman Tree, assigning shorter bit codes to more frequent characters.
3. Header Encryption: The serialized Huffman table is XORed against the user's password hash before being written to the file header.
4. Bit Packing: The payload is compressed bit-by-bit and packed into bytes for storage.

Data Structures

• Priority Queue: Used for efficient tree building (O(N log N)).
• Binary Trees: Used for traversing the bitstream during decompression.

Installation & Usage

Prerequisites

• C++ Compiler (g++ or clang)
• Make (optional)

Build

To compile the project manually:

g++ -o huffsecure main.cpp huffman.cpp -O3

Usage

Run the tool from the command line:

./huffsecure

Follow the interactive prompts:

1. Compress: Enter filename -> Enter Password -> Output generated (e.g., file.huf).
2. Decompress: Enter file.huf -> Enter Password -> Original file restored.

Note on Security: The current implementation uses XOR obfuscation, which is lightweight and efficient. It is intended to prevent casual access rather than defend against advanced cryptanalysis.

Project Structure

├── src/
│   ├── encoding.cpp       # Core Huffman algorithm implementation
│   ├── bitstream.cpp      # Low-level bit packing/unpacking logic
│   └── main.cpp           # CLI entry point
├── include/
│   └── encoding.h         # Header definitions
├── README.md
└── LICENSE

Future Improvements

• Replace internal educational libraries with standard C++ STL (std::priority_queue).
• Implement AES-128 encryption for robust security.
• Add multi-threading support for compressing large files.

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Author: Luka Aladashvili