It handles changing a password by keeping a file of the salts, which is theoretically safe to post to a public github (mine's in my dotfiles repo, though it's a private bitbucket repo)
edit: although, what happens if the dictionary is changed? It's the same on all Macs, but what about trying the same script on Linux?
@burrows: I think there's modulo bias here: https://github.com/burrows-labs/pz/blob/master/pz-master#L11 It probably doesn't matter much, but the displayed entropy estimate won't be exact.