steggo

A Least Significant Bit(s) Steganography (LSB) embedder/extractor. Takes a message and embeds it into an image file using LSB insertion.

Supported Input Formats

• PNG
• JPEG (outputs as <input_name>_jpeg_output.png)
  • The jpeg format has it's own built-in compression algorithm that will alter image pixels on save and the embedded message's integrity can't be guaranteed.
• BMP (outputs as <input_name>_bmp_output.png)
  • The bmp format only supports 256 colors. tl;dr - The LSB process modifies enough of these pixel colors that having a hard cap of 256 means there is no guarantee that the message can be extracted back out.

Check out the example/showcase

Run

Example Commands:

steggo embed --target path/picture.png --dest path/outputs/ --input "Words go here"

steggo extract --target path/outputs/picture_output.png

steggo embed --target path/another.png --dest path/outputs/ --input somefile.txt --pre-encoding r13,b64 # apply rot13 & base64 encoding

steggo extract --target path/outputs/another_output.png --dest path/extracted/
cat path/extracted/message.txt

What Wikipedia has to say about Steganography

Steganography is the practice of concealing a message within another message or a physical object. In computing/electronic contexts, a computer file, message, image, or video is concealed within another file, message, image, or video.

The advantage of steganography over cryptography alone is that the intended secret message does not attract attention to itself as an object of scrutiny. Plainly visible encrypted messages, no matter how unbreakable they are, arouse interest and may in themselves be incriminating in countries in which encryption is illegal.

^ If someone shared the message V293IHRoYXQgd2FzIGVhc3k= on Twitter it would be fairly obvious to most people that this may be some kind of computer code, and those in tech would probably see this and know that it's actually just base64 encoding... Whereas if someone shared a photo similar to what's in the example, the majority of people wouldn't think twice about it.

What is it?

Basically, take a secret message... "Hello!" for example and convert it from ASCII to binary:

    H        e        l        l        o        !
01001000 01100101 01101100 01101100 01101111 01000001

Break apart the message into an array of bits and hide them inside an image file's pixels using the Least Significant Bit(s) insertion. The emphasized text in the table below is the ASCII character split into 2-3-3 and embedded in an R-G-B pixel.

RGB	Encoded Character	RGB	Encoded Character	RGB	Encoded Character
10110101		01010101		11010101
10101001	H	10101100	e	10110101	l
10101000		10110101		11010100
10100101		10110101		10101101
11010101	l	10010101	o	10101000	!
10100100		10110111		10110001

TODOs

• Need to try a different approach to .gif embedding, seeing as it's a larger file type there's more opportunity for embedding larger messages (entire books, perhaps?) inside them.
• Frontend & REST server so there's a more user-friendly way of using steggo