Subject: [quicwg/base-drafts] d365a6: Prevent linkability from responding to migration

From: Martin Thomson <[email-masked]>
Date: Wed, 14 Aug 2019 19:45:02 -0700

Branch: refs/heads/respond-migration-cid
  Home:   https://github.com/quicwg/base-drafts
  Commit: d365a605731be5a2fce35bb8f545d51f96d241cd
      https://github.com/quicwg/base-drafts/commit/d365a605731be5a2fce35bb8f545d51f96d241cd
  Author: Martin Thomson <[email-masked]>
  Date:   2019-08-15 (Thu, 15 Aug 2019)

  Changed paths:
    M draft-ietf-quic-transport.md

  Log Message:
  -----------
  Prevent linkability from responding to migration

This closes the rather serious hole we left when we attempted to limit
the effect of perpetual changing of connection IDs.  This uses a
narrower formulation, that I believe will avoid perpetual changes.  But
it does require reciprocal connection ID changes where endpoints
genuinely do migrate.

It's a design change unfortunately, but I hope non-controversial.

Closes #2778.