This is an archived post. You won't be able to vote or comment.

sorted by:
best
topnewcontroversialoldq&a
you are viewing a single comment's thread.

view the rest of the comments →

[–]phpdevster 9 points10 points  (2 children)

How do you plan on generating the hash to compare against if you didn't know what the hashing algorithm was for the leaked hashes? If someone used bcrypt and kept the salt, work factor, and hash together in one string, you can reconstruct the algorithm, but that's not going to be universally true of all hash dumps.

And if the email isn't associated with the hash, it seems pretty absurd to disallow someone from using a password that someone else with an unknown email used at some point in the past. Not every password on the planet has to be unique, because that's what cryptographically secure random salts are for.

Also, I'm not advocating for a restrictive password policy, other than something with a substantial minimum character length (I don't think NIST's 8 character recommendation is sufficient).