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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Recent Updates

New Alpha Release: Tor 0.4.7.1-alpha

There's a new alpha release available for download. If you build Tor from source, you can download the source code for 0.4.7.1-alpha from the download page on the website. Packages should be available over the coming weeks, with a new alpha Tor Browser release likely some time next week.

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

This version is the first alpha release of the 0.4.7.x series. One major feature is Vanguards Lite, from proposal 333, to help mitigate guard discovery attacks against onion services. It also includes numerous bugfixes.

Changes in version 0.4.7.1-alpha - 2021-09-17

Major features (Proposal 332, onion services, guard selection algorithm):
- Clients and onion services now choose four long-lived "layer 2" guard relays for use as the middle hop in all onion circuits. These relays are kept in place for a randomized duration averaging 1 week. This mitigates guard discovery attacks against clients and short-lived onion services such as OnionShare. Long-lived onion services that need high security should still use the Vanguards addon (https://github.com/mikeperry-tor/vanguards). Closes ticket 40363; implements proposal 333.
Minor features (bridge testing support):
- Let external bridge reachability testing tools discard cached bridge descriptors when setting new bridges, so they can be sure to get a clean reachability test. Implements ticket 40209.

New Release: Tor Browser 10.5.6 (Windows, macOS, Linux)

Tor Browser 10.5.6 is now available from the Tor Browser download page and also from our

New Release: Tails 4.22

In Tails 4.22, we focused on solving the most important issues in the Tor Connection assistant to make it more robust and easier to use.