Re: [TLS] Possible blocking of Encrypted SNI extension in China

Peter Gutmann <pgut001@cs.auckland.ac.nz> Tue, 11 August 2020 07:14 UTC

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From: Peter Gutmann <pgut001@cs.auckland.ac.nz>
To: Christian Huitema <huitema@huitema.net>, Rob Sayre <sayrer@gmail.com>
CC: Christopher Wood <caw@heapingbits.net>, "TLS@ietf.org" <tls@ietf.org>
Thread-Topic: [TLS] Possible blocking of Encrypted SNI extension in China
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Date: Tue, 11 Aug 2020 07:14:41 +0000
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Subject: Re: [TLS] Possible blocking of Encrypted SNI extension in China
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Christian Huitema <huitema@huitema.net> writes:
 
>Defeating fingerprinting is really hard. It has been tried in the past, as in
>"make me look like Skype" or "make me look like wikipedia". The idea is to
>build a target model, then inject enough noise and padding in your traffic to
>match the target model. But that way easier to say than to do!

As Yuri Totrov, a.k.a the shadow director of personnel at the CIA, showed:

https://mindmatters.ai/2018/11/how-the-kgb-found-cia-agents/

the only way to hide A as B is if you become B.  Which means you can't be A
any more.  There was a paper that looked a traffic morphing published a year
or two ago that came to the same conclusion, to look like you're Skype or a
SIP VoIP call you need to actually be Skype or a SIP VoIP call.

Peter.