Steganography

A small python script that allows you to hide secret messages inside images and vice-versa

Requires Python3

Note(for Linux users):

Some Linux distros may not have pip installed by default. In that case, you may need to install it manually on your system. Users running a Debian based OS such as Ubuntu may install it by sudo apt install python3-pip
Additionally, the pyperclip module which has been used in this project depends on the OS to access the clipboard contents. Some Linux distros may not have certain packages to do so by default. Ubuntu, for example, lacks the required packages. Users running a Debian based OS such as Ubuntu may install the required package by sudo apt install xclip

Read the official pip and pyperclip documentation for more info...

Recommended execution style: Create a virtual python environment to house the dependencies of this project

Clone/extract this project into the required directory and then, fire up a terminal (or CMD in case of Windows) there and then create a python virtual environment there

Windows: python -m venv venv

Linux: python3 -m venv venv

Once the virtual environment has been created, activate it

Windows: venv\Scripts\activate.bat

Linux: source venv/bin/activate

You should see (venv) appear before your prompt in the terminal, indicating that the virtual environment has been activated... Then install the project requirements (The modules used are specified in the requirements.txt file)

Windows/Linux:pip install -r requirements.txt

Once the requirements have been satisfied, the script is ready to run...

Windows/Linux:python script.py

If you want to re-run the script, simply activate the virtual environment again and then run it by python script.py There is also a sample png image which has been included by the name of sample.png. You may use it for testing...

How does it work?

Two key functions are at play:

• get_binary(message)
• mutate(pixels)

In the get_binary function:

Basically, each word is separated by a @, which is then dealt with accordingly in the mutate function. The end of this so-called binary string is signified by the ! at the end which signals the program to stop reading the thing further.

>>> message
'ab'
>>> binary = []
>>> for i in message: binary += list(bin(ord(i))[2:].rjust(8, "0") + "@")
... 
>>> binary
['0', '1', '1', '0', '0', '0', '0', '1', '@', '0', '1', '1', '0', '0', '0', '1', '0', '@']
>>> binary = binary[: len(binary) - 1] + list("!")
>>> binary
['0', '1', '1', '0', '0', '0', '0', '1', '@', '0', '1', '1', '0', '0', '0', '1', '0', '!']

---

In the mutate function:

• we're going over each channel in this loop
• we're also reading the bits in our so-called binary string
• now, depending on the value of each bit, sy 1 or 0, (or even @), we change the vlaues of the channels slightly...
• this operation comes to a stop when the bit reads !
• the function decoding the image simply does the opposite of this this makes this program really non-standard and personally, kinda dumb lol

Limitations:

1. This script is CPU intensive
2. Works best on PNGs
3. The resulting PNG image loses its transparency (if any)
4. Some Unicode characters cannot be read properly... Using uncommon characters may break the code (all punctuations work fine though)
5. The max number of characters that can be encoded in an image depends upon its resolution... For example, an image of resolution 1920 by 1080 pixels can accommodate (1920*1080)/3 = 691200 characters only.
   
   

ENJOY!!

If you copy or distribute any part of this project, then be sure to give me some credit and show some love...
Feel free to contact me at [email protected]
Any feedback/suggestions would be highly valued...

</> with ♡, at GitHub