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Re: [TLS] TLS ECH, how much can the hint stick out?

"Blumenthal, Uri - 0553 - MITLL" <uri@ll.mit.edu> Fri, 11 September 2020 13:52 UTC

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From: "Blumenthal, Uri - 0553 - MITLL" <uri@ll.mit.edu>
To: "Salz, Rich" <rsalz=40akamai.com@dmarc.ietf.org>
CC: Christopher Patton <cpatton=40cloudflare.com@dmarc.ietf.org>, Christian Huitema <huitema@huitema.net>, "tls@ietf.org" <tls@ietf.org>
Thread-Topic: [TLS] TLS ECH, how much can the hint stick out?
Thread-Index: AQHWhfO58nZHN1CgFUWlh42sJM20lKlfDioAgAMs24CAAA5VgIAAVIYAgAATHYCAAMFPgIAAB2YA
Date: Fri, 11 Sep 2020 13:52:35 +0000
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Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/05Vm9_aczq39SFul3h6mjFbuIK8>
Subject: Re: [TLS] TLS ECH, how much can the hint stick out?
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IMHO, Rich is 100% correct here. 

If it’s not deployable (and to me it means **universally** deployable, not merely within the US), if fails *all* of the security goals completely. 

Regards,
Uri

> On Sep 11, 2020, at 09:27, Salz, Rich <rsalz=40akamai.com@dmarc.ietf.org> wrote:
> 
> 
> I think we should be careful with the word "broken" ... here we're talking about "don't stick out", which is a deployment consideration only. The main security goal is confidentiality of the ClientHelloInner.
>  
> Perhaps this is just being pedantic, but I disagree with the tone of this. We want deployable confidentiality, and “don’t stick out” is something we believe is a necessary requirement to be deployable.
>  
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