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Re:How To Safely Store A Password by Smerity on Friday July 01, 2011 @12:22AM (#2717047)
One possible option is challenge-response authentication. There a number of variations, but the simplest example is to hash both the hashed password and a nonce on both ends and check the resulting hash[1]. This means that the server only requires that the hashed password is stored, and the client never sends the password in plaintext as it generates the hash itself. As long as the nonce is unique each time, we can prevent replay attacks.

Various schemes introduce a client nonce and server nonce (to prevent man-in-the-middle attacks) or generate a shared secret nonce through methods similar to the Diffie-Hellman key exchange (so attackers can't work out the nonce).

[1] Ensure that h(h(passwd)+nonce) is equal on both ends where h(passwd) is either stored (server) or created by the user providing the plaintext password.

[2] http://en.wikipedia.org/wiki/Challenge-response_authenticati...

Re:How To Safely Store A Password by TwistedWave on Friday July 01, 2011 @07:26AM (#2717848)
The goal of hashing the passwords is to not store them in plaintext in the database, in case the server is compromised. In your case, an attacker doesn't need the password, the hash is enough to login.
Re:How To Safely Store A Password by roel_v on Friday July 01, 2011 @08:54AM (#2718073)
I suppose you mean "goal <...> is to not store them in plaintext"? I was confused there for a second.
Re:How To Safely Store A Password by TwistedWave on Friday July 01, 2011 @09:16AM (#2718173)
Indeed, thanks. I fixed it.