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Re: [TLS] PSK in 1.3?

Peter Gutmann <pgut001@cs.auckland.ac.nz> Mon, 20 October 2014 20:01 UTC

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From: Peter Gutmann <pgut001@cs.auckland.ac.nz>
To: "<tls@ietf.org>" <tls@ietf.org>
Thread-Topic: [TLS] PSK in 1.3?
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Date: Mon, 20 Oct 2014 20:00:59 +0000
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Subject: Re: [TLS] PSK in 1.3?
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Dan Harkins <dharkins@lounge.org> writes:

>There is nothing to flesh out because you seem to not understand what a
>dictionary attack is-- but you're in company because neither did the editors
>of that RFC.
>
>Protocols that use a static, symmetric credential like a PSK (or a password,
>the difference is semantic) are all flawed because the adversary is always
>assumed to have access to a pool from which the PSK (or password is drawn.

As Watson has already pointed out, the protocol name is "preshared key", not
"preshared password" as you seem to think.  I've been party to the deployment
of several PSK-based devices/systems, for which the pool from which the PSK is
drawn is well-known to an attacker, it ranges from 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 to FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF.  Since
I've now given you what you need to know, I'll let you go away and brute-force
the system.  Let us know when you're done.

Peter.

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