Talk:Hash Based Authentication

H needn't to be a trap-door hash function (no trap-door is used in the protocol). I am not sure about the proper requirement, though.

In my book, a trapdoor function is one that is practically non-invertible, that means that no good way to find a X so that H(X)=Y for a given Y is known and that one hopes this stays that way. That property certainly is required, or the game server can determine the user's password or something that is as good as the password.

-Z-Man (how do you automatically add a signature? The previous poster obviously doesn't know either :))