Steganography is the practice of concealing a file, message, image, or video within another file, message, image, or video.
This project implements a steganographic algorithm based on an arbitrary amount of customized text encryption layers. The text is read from an input plaintext file, encoded through several layers with a password, and mapped to the RGB values of an output image in PNG format, with adequate padding.
The input file must only contain ASCII characters
While initially the password was not required for the execution of application, it was decided to add an extra layer of security that could also work as a way to select the algorithms. It is important to note that most (if not all) algorithms implemented in this project are not secure by themselves, and combining them will probably only inconvenience an attacker. In order to select a password, please read the algorithm list.
In order to create a (more or less) compact image, the data is rear-padded with bytes sampled from the encoded data, seamlessly merging with the possible created colors. This allows for the image to maintain a squared shape and make it easier to visualize. So as to keep track of the padded bytes, a certain amount of bytes are added to the beginning of the data. The value obtained from these bytes indicate how many bytes were added at the end of the input data, making it possible to crop accurately when trying to decode. Therefore, the output image structure will follow the next format.
- N bytes of padding information (Defined in
src/utilities/image_conversions.py). - Encoded data.
- Up to
2^(N*8)bytes of padding, randomly selected from the encoded data.
Encoding plaintext file
python3 src/encoder.py <inputfile> <password>
Decoding images
python3 src/decoder.py <inputfile> <password>