[TLS] Certificate compression (a la QUIC) for TLS 1.3

Alessandro Ghedini <alessandro@ghedini.me> Sun, 27 November 2016 01:54 UTC

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Date: Sun, 27 Nov 2016 01:54:37 +0000
From: Alessandro Ghedini <alessandro@ghedini.me>
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Subject: [TLS] Certificate compression (a la QUIC) for TLS 1.3
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Hello,

not sure if this has been discussed before (apologies if it has).

QUIC mandates that certificate chains be gzip compressed in order to reduce the
amount of bytes transmitted during full handshake.

The QUIC crypto document says:

  Any remaining certificates are gzip compressed with a pre-shared dictionary
  that consists of the certificates specified by either of the first two
  methods, and a block of common strings from certificates taken from the
  Alexa top 5000.

https://docs.google.com/document/d/1g5nIXAIkN_Y-7XJW5K45IblHd_L2f5LTaDUDwvZ5L6g/edit#heading=h.fgd4sj5avil0

Has anyone though about including something like that in TLS 1.3?

Given that certificates usually take up most of the bytes exchanged during a
full handshake it seems this could be useful, but I don't know if in practice
the benefits are worth the added complexity. Thoughts?

Cheers