WebApp Sec mailing list archives

Re: At what layer to hash a password


From: Robin Wood <robin () digininja org>
Date: Mon, 28 Jun 2010 15:17:09 +0100

On 28 June 2010 09:55, Grega Bremec <gregab () p0f net> wrote:
On Sat, 2010-06-26 at 07:13 -0400, Tom Ritter wrote:
You covered several of the arguments: the password moving down the
stacks and being intercepted there, the maintainability.

But there's two more things I'd raise.  First off, you really shouldn't
be hashing your passwords.  It's better to use something I don't know
the correct term for (I've heard adaptive hashing and iterative hashing.
 I usually just call them by name).

I agree on not hashing.

Short of mentioning encryption in the transport layer (which is a must
in any such scenario), by far the most secure method involving passwords
known to me would be a challenge/response mechanism which completely
eliminates the need to transfer any kind of sensitive information over
the wire.

If the client produces the right token, the response to the challenge
will be identical to the one that the server calculated based on the PSK
at hand and the authentication can be thought of successful.

Nice once the PSK has been shared but when the user enters a password
for the first time you still have to protect it. I prefer systems
where I send out random passwords so can handle this kind of thing but
unfortunately a lot of clients, despite attempted education, prefer to
be able to let users enter their own passwords.

Robin



This list is sponsored by Cenzic
--------------------------------------
Let Us Hack You. Before Hackers Do!
It's Finally Here - The Cenzic Website HealthCheck. FREE.
Request Yours Now!
http://www.cenzic.com/2009HClaunch_Securityfocus
--------------------------------------


Current thread: