A Secret Message in an Image: Steganography
Channel: Dave Briccetti
Date: 28/08/2019

I show an apparently solid green image that actually contains two paragraphs of text, with one bit from each character of the text encoded into the low-order bit of the red component of the pixels. This is called steganography. I walk through a Python program that does this encoding and decoding. There are several moderately advanced concepts here, such as bit “twiddling” and numpy arrays, and I don’t cover them thoroughly. I consider this a first draft of what could be a really nice set of lessons building up to completely understanding this code.
One correction: Where you see an |= operator, I later changed that to a simple assignment, =.
https://github.com/dcbriccetti/StegaPy
Note: I’ve changed the code considerably since making this video. Please see the commit comments in Github for details.