Re: [TLS] Connection ID Draft

Stephen Farrell <stephen.farrell@cs.tcd.ie> Sun, 22 October 2017 15:50 UTC

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To: Eric Rescorla <ekr@rtfm.com>
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From: Stephen Farrell <stephen.farrell@cs.tcd.ie>
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Subject: Re: [TLS] Connection ID Draft
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On 22/10/17 16:41, Eric Rescorla wrote:
> 
>> Maybe the thing we could agree at this stage is that the cid scheme
>> has to be usable in that one-message-per-day scenario and needs to
>> provide some way that such messages aren't easily linkable based on
>> cids.
> 
> I think that's a requirement in some cases but not others. It might be
> best to settle for the others.

Sorry, I'm not sure what you mean there. Are you saying that you think
the above requirement can't be met by a generally usable scheme?

I agree that not all scenarios need to meet the req posited above.

I'd worry that if DTLS1.3 can't meet the above requirement then folks
will invent something that does, which may be worse than using DTLS
in a bunch of cases. OTOH, one could equally, and maybe fairly, argue
that DTLS really doesn't scale down quite that far, which'd I guess
argue that there's a need for some other security protocol for those
situations.

S.

PS: I fully accept your point that purely napkin-based schemes aren't
good enough and if those're the only kind of hash-chain based proposals
seen, then the WG oughtn't go for one of those.