Below are the major changes of the released versions and links to more detailed release notes.
Today, we release the first stable version of the 0.4.7.x series fixing several major bugfixes, several major features and, finally after years of work, congestion control. See the Release Notes section below for the full detailed list of changes. Here are two major features worth mentioning:
This stable series of Tor contains an implementation of RTT-based congestion control detailed in proposal 324.
Congestion control will eliminate the speed limit of current Tor, as well as avoid large queue lengths at relays. It will result in significant performance improvements in Tor, as well as increased utilization of our network capacity.
It requires Exit relays to upgrade in order to be used by 0.4.7 clients. We will be posting a blog post with further technical details, as well as upgrade instructions for Exit relays.
Onion Service Vanguard
Onion service clients and services automatically select four long-lived layer 2 guard relays to be used as the middle hop. These relays are kept in place for a randomized duration averaging 1 week.
This is a defense meant to counter de-anonymization attacks on onion services. More details can be found in proposal 333.
To all our beloved packagers, we encourage you to please prepare packages with this release as soon as you can, to help this important network upgrade process.
Once packages are out, we strongly encourage all Exit operators to upgrade to this stable release.