NIST proposes barring some of the most nonsensical password rules
NIST proposes barring some of the most nonsensical password rules
Here is the text of the NIST sp800-63b Digital Identity Guidelines.
Hashing passwords isn't even best practice at this point, it's the minimally acceptable standard.
What is the best practice currently?
Use a library. It's far too easy for developers or project managers to fuck up the minimum requirements for safely storing passwords.
But, if you are wanting to do it by hand...
Salt the hash with something unique to that specific user so identical passwords have different hashes
Isn't that... the very definition of a Salt? A user-specific known string? Though my understanding is that the salt gets appended to the user-provided password, hashed and then checked against the record, so I wouldn't say that the hash is salted, but rather the password.
Also using a pepper is good practice in addition to a salt, though the latter is more important.
Some implementers reuse the same salt for all passwords. It's not the worst thing ever, but it does make it substantially easier to crack than if everything has its own salt.
That's a pepper not a salt. A constant value added to the password that's the same for every user is a pepper and prevents rainbow table attacks. A per-user value added is a salt and prevents a number of things, but the big one is being able to overwrite a users password entry with another known users password (perhaps with a SQL injection).
Sorta. Not really.
Key derivation algorithms are still hashes in most practical ways. Though they're derived directly from block ciphers in most cases, so you could also say they're encrypted. Even though people say to hash passwords, not encrypt them.
I find the whole terminology here to be unenlightening. It obscures more than it understands.
A KDF is not reversible so it's not encryption (a bad one can be brute forced or have a collision, but that's different from decrypting it even if the outcome is effectively the same). As long as you're salting (and ideally peppering) your passwords and the iteration count is sufficiently high, any sufficiently long password will be effectively unrecoverable via any known means (barring a flaw being found in the KDF).
The defining characteristic that separates hashing from encryption is that for hashing there is no inverse function that can take the output and one or more extra parameters (secrets, salts, etc.) and produce the original input, unlike with encryption.
OK. How do you reconcile that with "Hashing passwords isn't even the best practice at this point"? Key derivation functions are certainly the recommended approach these days. If they are hashes, then your earlier post is wrong, and if they aren't hashes, then your next post was wrong.
The rest of that sentence is important. Hashing passwords is the minimum practice, not best practice. You should always be at least hashing passwords. Best practice would be salting and peppering them as well as picking a strong hashing function with as high a number of iterations as you can support. You would then pair that with 2FA (not SMS based), and a minimum password length of 16 with no maximum length.
