>>3698059 (lb)

There is nothing to figure out. If you have an image you are sure contains a hidden message then you'd have to find a way of brute-forcing the password. Could take years on a modest home computer. Wanna waste your time on that?

When Q mentioned that (((they))) used steganography he wasn't asking us to try to crack open hidden messages. He was just informing us that it was a method they used to conceal their messages. That is all.