[werner34]

You are reducing the room of possible passwords quite a lot, I am not sure if that is a good idea.

Firstly e.g. for MD5 your hashes are never going to contain Letters > f, no uppercase and no special characters.

Secondly you are limiting the possible passwords to hashes of short natural language strings.

[antjanus]

Yes, definitely. I think I mentioned in there that I will be expanding the process beyond just MD5 and SHA1 (that was pretty much the prototype). I'm hoping to create my own "hashing"-type process to allow all letters, uppercase/lowercase, and so on.