Least Significant Bit Steganography

Version: 3.0.0

Authors: Andrew Quach and Stanislav Lyakhov

Introduction

Steglsb has two functions: Stenographic LSB encoding and decoding. Encoding embeds a secret image in the last significant bits of a cover image. Decoding extracts a secret image from an steganographic image using LSB.

Each mode of steglsb [-d/-e] requires an argument detailing the number of bits. In other words, the number of rightmost bits of each pixel used in encoding and decoding.

EX: If bits = 3, the LSB of 11011010 is 010.

A larger number of bits specified means a higher steganographic capacity. However, it also means a more visible secret.

Usage

Encoding:

Usage: steglsb.py -e cover_img secret_img bits outfile [mode]

> Embed a secret image into a cover image using LSB

    Positional Arguments:
        cover_img  - path to cover image
        secret_img - path to secret image
        bits       - number of rightmost bits to use (between 0-8)
        outfile    - path to output file
    Optional Arguments:
        mode       - image mode to use 'RGB', 'RGBA', 'L', 'CMYK'

Notes: The cover image should be larger than the secret image.
       The mode defaults to the mode of the cover image.
       CMYK LSB is not optimal. It is recommended to force CMYK to RGB. 

Decoding:

Usage: steglsb.py -d steg_img bits outfile

> Extract a secret image from a steganographic image using LSB

    Positional Arguments:
        steg_img   - path to steg image
        bits       - number of rightmost bits to use (between 0-8)
        outfile    - path to output file

Usage Examples:

Encoding Example: Insert 'secret.jpg' into the image 'cover.png' located in the 'example' folder
                  Type the following command: './steglsb.py -e example/cover.png example/secret.jpg 2 output.png'
                  The program will run and create the file 'output.png'
                  'output.png' will look like 'cover.png' but contain 'secret.jpg'

Decoding Example: There is a secret image in hidden.png
                  Type the following command: './steglsb.py -d example/hidden.png 2 secret.png'
                  The secret image is hidden in the last 2 LSBs.
                  A 'secret.png' file will be created containing the secret image.

Dependencies

This program depends on Python3 Pillow.

Installation Using Pip:

sudo apt-get install python3-pip
sudo pip3 install Pillow