Steganography - Hide

I am just playing around with ideas from steganography. Right now, all this does is hide bytes in the least significant bits of an image. Images are saved as 100% quality PNGs - there is no protection against compression (yet). PIL is required.

Hiding Text

To use the sample and hide some text in a PNG image type

python sample.py -f out hide path/to/source/image.jpg

(will save in out.png) and

python sample.py show out.png

Hiding files

To use the sample and hide an arbitrary file in a PNG image type

python sample2.py -f <file_to_hide> hide path/to/source/image.jpg

This will create path/to/source/image.jpg_out.png. To extract a file from such a generated PNG file, use

python sample2.py show path/to/source/image.jpg_out.png -f <filename>

and the hidden file will be written to <filename>

Getting a file-like object

The following code

import stegwrapper

p = stegwrapper.picture.open("filename", "w")

creates an object p much like the file objects in python. You can use read(n) and write(str) to read and write bytes from/to the image. seek, tell and close are implemented as well. The idea is that you can (steganographically) save what you have read from a file directly into the picture:

file = open('some_binary_file', 'rb')
pic  = stegawrapper.picture.open('hide_stuff_here.png', 'w')

byte = file.read(1)
pic.write(byte)

The overhead in sample2.py is just to give it a command line interface and to save the size of the hidden file into the first few steganographic bytes as well.