Hi, I'm taking a programming class at my school. My teacher gave us a pdf that said "..You will be writing a program that can read a bitmap and insert a secret message into the bytes of the picture in a retrievable way using the picture as a cipher and return the original message. This is a type of encryption that is very easy to accomplish and very difficult to decipher or uncover. It both ends of the communication have the same original picture, then deciphering is asimple matter of filtering out the original, and all you have left is the message."
He hasn't assigned it yet, but I just want to know if that is possible while keeping the original picture with the secret message in the bitmap or whatever we're using. Like having the message "stuffffff" in the picture, but have the picture look the same as the original.