Re: [quicwg/base-drafts] Linkability with preferred_address usage (#3559)

Mike Bishop <notifications@github.com> Tue, 31 March 2020 19:59 UTC

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Date: Tue, 31 Mar 2020 12:59:42 -0700
From: Mike Bishop <notifications@github.com>
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Subject: Re: [quicwg/base-drafts] Linkability with preferred_address usage (#3559)
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A server that wants to defeat linkability always can.  Using `preferred_address`, a server could easily enough issue each client its own IPv6 address or, even with IPv4, a unique ephemeral port.  Even without it, a server could issue trivially linkable CIDs, disclose its CID key, etc.  So the goal is to reduce the chances that this happens accidentally, not to prevent it entirely.

We already decided not to prohibit active migration in the presence of zero-length CIDs, IIRC.  Given that, I think this is just a textual warning to be cautious in this circumstance.

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