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Re: [TLS] Cleaning up 0-RTT Signaling (ciphersuites, replays, PSK context)

Eric Rescorla <ekr@rtfm.com> Fri, 25 March 2016 18:37 UTC

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From: Eric Rescorla <ekr@rtfm.com>
Date: Fri, 25 Mar 2016 11:36:29 -0700
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To: Colm MacCárthaigh <colm@allcosts.net>
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Subject: Re: [TLS] Cleaning up 0-RTT Signaling (ciphersuites, replays, PSK context)
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On Fri, Mar 25, 2016 at 11:27 AM, Colm MacCárthaigh <colm@allcosts.net>
wrote:
>
> +1 but I think we can go further here and specify 0RTT in such a way that
> it only works when the server maintains state, and so that any given 0RTT
> ticket may only be used once (to preserve forward secrecy as much as
> possible within the constrains of 0RTT).
>

I'm not enthusiastic about this. This seems like it would rule out a bunch
of implementations
which don't need that guarantee.

-Ekr


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