Easy C# Steganography Tool to Hide Text in Images 🖼️

A simple steganography tool that allows the user to hide text in images. I wrote this a year and a half ago when I was fairly new to C# and coding, but I think the idea is still cool and worth sharing.

---How it works---
I think there are a quite a few ways to do this sort of thing, but my research lead me to this method (I think it's known as the bit of least significance method). For those who know a little about this, a png image file, like pretty much any other file, is a grouping of bytes. Each byte has eight bits, and these bits (ones and zeros) are what ultimately dictate the pixels' colors and make up the image you see. This tool grabs the bytes responsible for the pixel makeup, takes the last bit in each byte, the bit of least significance, and exchanges it with a bit of a byte of the data that you are injecting (if that's the right word) into the image. So basically, each byte of the image makes up 1/8th a a byte of the data, but since there are many bytes in a decent sized png image, you can store a lot of text. Anyway, that's my simple explanation. This type of concealment has been used by terrorist organizations as well as intelligence agencies. You can upload these images online or use them as forum avatars and people can then download them and decode a secret message (assuming the host doesn't re-size the image or tamper with it in some other way).

I'm guessing a lot of the code in this is very sloppy, but I'll give it to anyone who would like to learn from it and maybe make a more advanced tool (since all files are made up of bytes, you can hide text, music, even other images in the image, or you can hide media in music, videos, or almost anything else.

I dug up the tutorial I referenced most frequently in writing this: http://www.dreamincode.net/forums/topic/27950-steganography/
It's for Java, not C#, but adjusting the syntax is not difficult. I also grabbed a class online to extract the pixel data from a bitmap (note: if you simply serialize the image, you might tamper with its metadata when you encode it, which can have very bad effects). C# offers some managed solutions for getting pixels one by one, but it's much slower, so I recommend my approach.

Binary: http://www.mediafire.com/download/d8vwlmeagsppasl/Encoder.zip