BridgeDB ========

* We submitted our "gather BridgeDB usage statistics" proposal to the Tor research safety board. You can find the proposal it here: https://lists.torproject.org/pipermail/anti-censorship-team/2019-April/000004.html We are still waiting to hear back from the board.

* We filed https://bugs.torproject.org/30441 to understand why BridgeDB is handing out so many offline bridges. It looks like this problem is a combination of several smaller problems. We wrote a tool that scans the obfs4 port of all bridges that our bridge authority knows about, and started contacting the operators of bridges whose obfs4 port was unreachable. Have a look at the ticket for details.

GetTor ======

* We deployed the refactored GetTor codebase: https://bugs.torproject.org/28152

Pluggable transports ====================

* We built a service that allows bridge operators to scan the obfs4 port of their bridge. The service is now deployed and available at https://bridges.torproject.org/scan/. Give it a try and tell us what we can do better! - The ticket is available here: https://bugs.torproject.org/30472 - The code is available here: https://github.com/NullHypothesis/obfs4PortScan - This effort is part of improving the UX of setting up an obfs4 bridge: https://trac.torproject.org/projects/tor/ticket/30471.

* We revised our obfs4 setup instructions: https://trac.torproject.org/projects/tor/wiki/doc/PluggableTransports/obfs4proxy - This effort is part of improving the UX of setting up an obfs4 bridge: https://trac.torproject.org/projects/tor/ticket/30471.

* We assessed the HTTPS Proxy pluggable transport; i.e., understood its advantages, disadvantages, and what it would take to deploy it. Our assessment is available at https://trac.torproject.org/projects/tor/ticket/29278#comment:6.

Censorship analysis ===================

* We are in touch with a research group that is studying the GFW's active probing system. We noticed that the GFW does not probe recent Tor versions. One explanation is that the cipher list in Tor's TLS client hello (this is what the GFW uses to identify Tor) changed. - See https://bugs.torproject.org/30500 for the ticket.

* We recently saw a drastic increase of Tor users from Iran. We don't yet understand the reason for this. - See https://bugs.torproject.org/projects/30636 for details.

Snowflake =========

* We made progress with snowflake's WebExtension. - See https://bugs.torproject.org/23888 for details.

* We started working on detailed measurements of the snowflake blocking in China. We saw Google's STUN servers starting to be blocked in China, as well as blocking stop for individual proxies. - See https://bugs.torproject.org/30368 for the ticket.

* Fixed several bugs in the client and snowflake proxy-go instances.

* Starting locally collecting geo-IP metrics on snowflake proxies.

* Fought a broker outage and implemented a fall-back mechanism for using snowflake certificates - See https://bugs.torproject.org/30512 and https://bugs.torproject.org/30509.

Miscellaneous =============

* We finished a technical report as deliverable for Sponsor 19. The report provides a comprehensive overview of the state of Tor's anti-censorship efforts and we will soon publish it in a blog post.

* We attended the kick-off meeting for Sponsor 28. As part of this project we will keep improving snowflake, improve and evaluate the obfs4 protocol, and extend our pluggable transport specification. - See the following page for Sponsor 28-related work: https://trac.torproject.org/projects/tor/wiki/org/sponsors/Sponsor28