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Re: [Ppm] Timestamps and nonces

Tim Geoghegan <timg@letsencrypt.org> Thu, 30 June 2022 16:08 UTC

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From: Tim Geoghegan <timg@letsencrypt.org>
Date: Thu, 30 Jun 2022 09:06:45 -0700
Message-ID: <CABN231o4ueytG83Sb4BL6K2ez7R02Sc+AA4REtGgtVz97Sfa2g@mail.gmail.com>
To: Christopher Wood <caw@heapingbits.net>
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Subject: Re: [Ppm] Timestamps and nonces
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I believe the relevant pull request is
https://github.com/ietf-wg-ppm/draft-ietf-ppm-dap/pull/281

I commented over on GitHub, and I think this is a great idea. Thanks to
Shan for raising it!

Tim

On Thu, Jun 30, 2022 at 7:28 AM Christopher Wood <caw@heapingbits.net>
wrote:

> One issue pointed in #274 is that the timestamps might be used to link
> reports to clients as reports move throughout the system. This is somewhat
> of a problem, especially for deployments that want to apply shuffling for
> the purposes of amplifying local DP effects. Since the timestamp is really
> only used to identify the window in which replay protection should be
> applied, one solution to this problem is to make the timestamp less precise
> (a multiple of the batch window start time) and then bump up the nonce size
> to account for collisions. This approach is spelled out in this PR:
>
>    https://github.com/ietf-wg-ppm/draft-ietf-ppm-dap/pulls
>
> Please have a look and provide feedback.
>
> Thanks,
> Chris
> --
> Ppm mailing list
> Ppm@ietf.org
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>

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