Download Tor Browser 5.5

Version 5.5 of Tor Browser has been released. Tor stands for The Onion Router and is a network that can be used to surf the Internet fairly anonymously. All users’ tcp traffic is routed through various Tor routers, after which it is virtually impossible for the receiver to trace who the original sender was. This information is still present within the Tor network, so that answers, of course also via the system of routers, eventually arrive at the right place. Based on Firefox Extended Support Release version 38.6, this release contains the following changes and improvements:

Tor Browser 5.5 has been released

Tor Browser 5.5, the first stable release in the 5.5 series, is now available from the Tor Browser Project page and also from our distribution directory. This release features important security updates to firefox.

On the privacy front we finally provide a defense against font enumeration attacks which we developed over the last weeks and months. While there is still room for improvement, it closes an important gap in our fingerprinting defenses. Additionally, we isolate Shared Workers to the first-party domain now and further improved our keyboard fingerprinting defense.

We also made progress on the usability side. First, by providing Tor Browser in another locale, Japanese. Additionally, by showing the changes in the new Tor Browser version immediately after an update and polishing our about:tor appearance. Last but not least we changed the search bar URL for the DuckDuckGo search engine to its onion URL.

Here is the full changelog since 5.0.7:

All Platforms

• Update Firefox to 38.6.0esr
• Update libevent to 2.0.22-stable
• Update NoScript to 2.9.0.2
• Update Torbutton to 1.9.4.3
  • Bug 16990: Show circuit display for connections using multi-party channels
  • Bug 18019: Avoid empty prompt shown after non-en-US update
  • Bug 18004: Remove Tor fundraising donation banner
  • Bug 16940: After update, load local change notes
  • Bug 17108: Polish about:tor appearance
  • Bug 17568: Clean up tor-control-port.js
  • Bug 16620: Move window.name handling into a Firefox patch
  • Bug 17351: Code cleanup
  • Translation updates
• Update Tor Launcher to 0.2.7.8
  • Bug 18113: Randomly permutate available default bridges of chosen type
• Bug 13313: Bundle a fixed set of fonts to defend against fingerprinting
• Bug 10140: Add new Tor Browser locale (Japanese)
• Bug 17428: Remove Flash Proxy
• Bug 13512: Load a static tab with change notes after an update
• Bug 9659: Avoid loop due to optimistic data SOCKS code (fix of #3875)
• Bug 15564: Isolate SharedWorkers by first-party domain
• Bug 16940: After update, load local change notes
• Bug 17759: Apply whitelist to local fonts in @font-face (fix of #13313)
• Bug 17009: Shift and Alt keys leak physical keyboard layout (fix of #15646)
• Bug 17790: Map the proper SHIFT characters to the digit keys (fix of #15646)
• Bug 17369: Disable RC4 fallback
• Bug 17442: Remove custom updater certificate pinning
• Bug 16620: Move window.name handling into a Firefox patch
• Bug 17220: Support math symbols in font whitelist
• Bug 10599+17305: Include updater and build patches needed for hardened builds
• Bug 18115+18104+18071+18091: Update/add new obfs4 bridge
• Bug 18072: Change recommended pluggable transport type to obfs4
• Bug 18008: Create a new MAR Signing key and bake it into Tor Browser
• Bug 16322: Use onion address for DuckDuckGo search engine
• Bug 17917: Changelog after update is empty if JS is disabled

Windows

• Bug 17250: Add localized font names to font whitelist
• Bug 16707: Allow more system fonts to get used on Windows
• Bug 13819: Ship expert bundles with console enabled
• Bug 17250: Fix broken Japanese fonts
• Bug 17870: Add intermediate certificate for authenticode signing

OS X

• Bug 17122: Rename Japanese OS X bundle
• Bug 16707: Allow more system fonts to get used on OS X
• Bug 17661: Whitelist font .Helvetica Neue DeskInterface

Linux

• Bug 16672: Don’t use font whitelisting for Linux users