Re: [TLS] draft-dkg-tls-reject-static-dh

R duToit <> Wed, 05 December 2018 19:47 UTC

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Date: Wed, 05 Dec 2018 14:47:03 -0500
From: R duToit <>
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Subject: Re: [TLS] draft-dkg-tls-reject-static-dh
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1. Perhaps the kind folks at Qualsys have some recent stats for us, given that they track DH reuse under "Protocol Details" when you run their tool. 2. The DoS (prevention) engineers should also weigh in on this.  Would servers not start reusing TLS 1.3 keyshare values when under DoS attack? --Roelof ---- On Wed, 05 Dec 2018 14:34:44 -0500 Viktor Dukhovni <> wrote ---- > On Dec 5, 2018, at 2:19 PM, R duToit <> wrote: > > Quote: "As we will discuss later, we empirically find that at least 7.2% of HTTPS domains in the Alexa Top Million reuse DHE values and 15.5% reuse ECDHE values." That survey is now dated. Library defaults matter, and it used to be the case in OpenSSL that it was all to easy to re-use (EC)DHE keys. This is no longer the case, and if that survey were repeated today, servers not running unpatched EOL code would not re-use (EC)DHE keys. I rather expect the amount of re-use is much lower now, and will be essentially zero in the next couple of years (as most of the remaining outdated software is replaced). Some Internet metrics can change in just a few years. --     Viktor. _______________________________________________ TLS mailing list