Reading the description I was wondering how it was working because it says during encoding it hashes the image to create a key and during decoding it hashes the

Reading the description I was wondering how it was working because it says during encoding it hashes the image to create a key and during decoding it hashes the image to create a key. But if it is hashing the whole image these keys cannot be the same. But when you look at the code it is not hashing the whole image. It is only hashing a subset of the bits. :)