SteganoPNG

C++ program based on steganographical methods to hide files in PNG images using the Least Significant Bit technique.

SteganoPNG uses the most basic method which is the least significant bit. A pixel in a PNG image is composed of a red, green, blue and alpha channel encoded in one byte each. The least significant bit was chosen to visually modify the image as little as possible.

Information

SteganoPNG uses LodePNG to hide data in PNG files. It uses the first bit of each color channel, including the alpha channel, of a pixel. The program can hide all of the data if there is enough space in the image. You need roughly twice as many pixels as bytes you want to hide (Unless compression is enabled).

Only PNG files are supported to obtain maximum storage capacity within the image.

Additionally Crypto++ is used to provide AES256-CBC encryption/decryption and compression/decompression support. Compression/Decompression is enabled by default but can be disabled via the --no-compression commandline argument. Furthermore the modified data is placed pseudo-randomly within the image to make detection much harder.

Installation

Download a precompiled binary on the releases tab or compile them yourself. The provided binaries are 64-bit builds.

Building

Requirements

• A compiler capable of compiling C++17 code
• Aditionally on unix systems GNU Make
• Optionally on either platform cmake for more features

First clone this repo with git clone --recurse-submodules.

Building on unix systems is greatly simplified by using a Makefile. Simply run make inside the project folder. Building on unix requires the C++ compiler g++ version 8 to be installed.

Building on windows is as simple as cloning the repository into Visual Studio 2019 and building the Release or Debug configuration.

The Release-Zopfli and Debug-Zopfli configurations on Windows contain stronger compression provided by Zopfli but are slightly slower and are disabled by default.

If you wish to enable them on unix please run make CPPFLAGS=-DUSEZOPFLI instead.

For information on how to use the feature please run SteganoPNG -h .

Usage

SteganoPNG

Syntax: SteganoPNG <command> <image.png> [data.xyz] [-p <password>] [--no-compression]

Commands:
        a       Hide provided file in image
        x       Extract file hidden in image
        t       Verify if the image contains enough pixels for storage
        h       Show this help screen

Examples:
        SteganoPNG a image.png FileYouWantToHide.xyz  to hide "FileYouWantToHide.xyz" inside image.png
        SteganoPNG x image.png                        to extract the file hidden in image.png
        SteganoPNG t image.png FileYouWantToHide.xyz  to verify that the image contains enough pixels for storage

Dependencies

This program depends on LodePNG. LodePNG is licensed under the zlib license.

This program also requires Crypto++.

Optionally Zopfli can be added to enable better compression. Zopfli is licensed under the Apache License 2.0.

License

This software is MIT-Licensed.