entry guards | Tor Blog

Tor security advisory: "relay early" traffic confirmation attack

This advisory was posted on the tor-announce mailing list.

277 comments

Improving Tor's anonymity by changing guard parameters

There are tensions in the Tor protocol design between the anonymity provided by entry guards and the performance improvements from better load balancing.

67 comments

The lifecycle of a new relay

Many people set up new fast relays and then wonder why their bandwidth is not fully loaded instantly.

49 comments

Research problem: better guard rotation parameters

Tor's entry guard design protects users in a variety of ways.

16 comments

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New release: Tor 0.3.5.1-alpha

There's a new alpha release available for download. If you build Tor from source, you can download the source code for 0.3.5.1-alpha from the usual place on the website. Packages should be available over the coming weeks, with a new alpha Tor Browser release some time this week.

Remember, this is an alpha release: you should only run this if you'd like to find and report more bugs than usual.

Tor 0.3.5.1-alpha is the first release of the 0.3.5.x series. It adds client authorization for modern (v3) onion services, improves bootstrap reporting, begins reorganizing Tor's codebase, adds optional support for NSS in place of OpenSSL, and much more.

Changes in version 0.3.5.1-alpha - 2018-09-18

Major features (onion services, UI change):
- For a newly created onion service, the default version is now 3. Tor still supports existing version 2 services, but the operator now needs to set "HiddenServiceVersion 2" in order to create a new version 2 service. For existing services, Tor now learns the version by reading the key file. Closes ticket 27215.
Major features (relay, UI change):
- Relays no longer run as exits by default. If the "ExitRelay" option is auto (or unset), and no exit policy is specified with ExitPolicy or ReducedExitPolicy, we now treat ExitRelay as 0. Previously in this case, we allowed exit traffic and logged a warning message. Closes ticket 21530. Patch by Neel Chauhan.
- Tor now validates that the ContactInfo config option is valid UTF- 8 when parsing torrc. Closes ticket 27428.

New Release: Tor 0.3.4.8 (also other stable updates: 0.2.9.17, 0.3.2.12, and 0.3.3.10)

After months of work, we have a new stable release series! If you build Tor from source, you can download the source code for 0.3.4.8 on the download page of the website. Packages should be available within the next several weeks, with a new Tor Browser by some time next week.

Additionally, we're also releasing updates today for the older supported release series: 0.2.9.17, 0.3.2.12, and 0.3.3.10 . You can find them at dist.torproject.org.

Tor 0.3.4.8 is the first stable release in its series; it includes compilation and portability fixes.

The Tor 0.3.4 series includes improvements for running Tor in low-power and embedded environments, which should help performance in general. We've begun work on better modularity, and included preliminary changes on the directory authority side to accommodate a new bandwidth measurement system. We've also integrated more continuous-integration systems into our development process, and made corresponding changes to Tor's testing infrastructure. Finally, we've continued to refine our anti-denial-of-service code.

Below are the changes since 0.3.3.9. For a list of only the changes since 0.3.4.7-rc, see the ChangeLog file.

Changes in version 0.3.4.8 - 2018-09-10

New system requirements:
- Tor no longer tries to support old operating systems without mmap() or some local equivalent. Apparently, compilation on such systems has been broken for some time, without anybody noticing or complaining. Closes ticket 25398.
Major features (directory authority, modularization):
- The directory authority subsystem has been modularized. The code is now located in src/or/dirauth/, and is compiled in by default. To disable the module, the configure option --disable-module-dirauth has been added. This module may be disabled by default in some future release. Closes ticket 25610.