docs/releases/v3.2.2.rst
Security fixes
* The XSRF token is now encoded with a random mask on each request.
This makes it safe to include in compressed pages without being
vulnerable to the `BREACH attack <http://breachattack.com>`_.
This applies to most applications that use both the ``xsrf_cookies``
and ``gzip`` options (or have gzip applied by a proxy).
Backwards-compatibility notes
.Application setting xsrf_cookie_version=1 can
be used for a transitional period to generate the older cookie format
on newer servers.Other changes
* ``tornado.platform.asyncio`` is now compatible with ``trollius`` version 0.3.