Re: [apps-discuss] [http-state] HTTP MAC Authentication Scheme

Nico Williams <> Tue, 07 June 2011 17:35 UTC

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Date: Tue, 7 Jun 2011 12:35:52 -0500
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From: Nico Williams <>
To: "Paul E. Jones" <>
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Cc:, Ben Adida <>, Adam Barth <>,, HTTP Working Group <>, OAuth WG <>
Subject: Re: [apps-discuss] [http-state] HTTP MAC Authentication Scheme
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On Mon, Jun 6, 2011 at 10:25 PM, Paul E. Jones <> wrote:
> Nico,
> Sorry for coming into this so late, but I just saw this message.
> I don't have all of the background, but when I saw this message header and
> some of the dialog, it seems there is a desire to provide some level of
> authentication to requests and/or responses between the clients and servers.
> Gonzalo and I worked on this:
> This may not be entirely complete, but the idea was to allow a client and
> server to establish an association so that requests and responses could be
> authenticated.  Is this something along the lines of what you are
> discussing, or is this an entirely different application?

I'm completely on-board with session state[*].  My comments were
particularly in regards to threat models.  I believe that
eavesdroppers and active attackers both need to be considered,
particularly as we have so many open wifi networks.

To me the simplest way to address the Internet threat model is to
always use TLS (except, maybe, for images and such elements that have
little or no security value, though one must be careful when making
that determination) and to use channel binding.  See the I-D
referenced below.

[*]  See, for example: