Re: [tcpm] Privacy problems of TCP Fast Open

Erik Sy <sy@informatik.uni-hamburg.de> Mon, 20 May 2019 21:19 UTC

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From: Erik Sy <sy@informatik.uni-hamburg.de>
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Date: Mon, 20 May 2019 23:19:26 +0200
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Subject: Re: [tcpm] Privacy problems of TCP Fast Open
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I think it is important to warn users about the privacy risks of RFC
7413. For example, Mozilla reacted to the privacy problems of TCP Fast
Open by deprecating this protocol on all it's Firefox branches. In
total, TCP Fast Open has significant issues with respect to user
privacy, performance and deployment on the real-world Internet. From my
point of view, it is about time to deprecate RFC 7413.

Regards,
Erik

On 5/10/19 14:14, Erik Sy wrote:

> Hi everyone,
>
> TCP Fast Open has significant privacy problems which are not considered
> in RFC 7413.
> For example, this protocol allows a passive network observer to
> correlate connections established by the same client, which protocols
> such as TLS 1.3 and QUIC actively protect against. Furthermore, Fast
> Open cookies present a kernel-based tracking mechanism which is quite
> persistent. Amongst others, they can be used to conduct cross-browser
> tracking on the same operating system.
> For further details please refer to this article:
> https://arxiv.org/pdf/1905.03518.pdf
>
> I suggest, that the working group takes steps to highlight these privacy
> problems of RFC 7413.
>
> Regards,
> Erik
>
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