The Tor Project has introduced a significant update with its Version 3 protocol, marking a substantial improvement over its predecessor, Tor v2. This article explores the new features and enhancements that come with Tor Version 3, available for Windows, macOS, and Linux. The Tor Browser 7.5a51 is the first to support the v3 protocol.

For macOS users, installing the new version is straightforward with the command brew install tor in the terminal (assuming you have Homebrew2 installed). Once installed, check your version with tor version to ensure it’s at least Tor 0.3.2.1 or higher.

Key Features of Tor v3, also known as prop224 34

With the implementation of v3 starting from Tor version 0.3.2.1-alpha, several enhancements have been introduced:

  1. Upgraded Security Protocols: Transitioning to SHA3, ed25519, and curve25519, replacing the older SHA1, DH, and RSA1024. This shift significantly enhances the cryptographic strength of the network.

  2. Improved Directory Protocol: The new protocol reduces the amount of information that directory servers can leak, enhancing user privacy.

  3. Resilience Against Attacks: Directory servers now have a reduced impact when encountering attacks, ensuring more robust network stability.

  4. Enhanced Onion Addresses: The shift to SHA3 for onion addresses increases the difficulty of brute-forcing these addresses.

  5. Scalable Exchange Protocol: The v3 protocol introduces a more flexible and scalable exchange protocol5.

  6. Refined and Modular Codebase: The underlying code of Tor has been streamlined and modularized, making it more efficient and easier to maintain.

Comparison: v2 vs. v3 Onion Domains

The most noticeable difference between v2 and v3 is in the length of the onion domain names. Longer domain names in v3 significantly reduce the feasibility of attackers successfully generating identical domains, a tactic used in phishing attacks.

  • v2 Domain Example: cryptolk2jn53pi7.onion
  • v3 Domain Example: 4acth47i6kxnvkewtm6q7ib2s3ufpo5sqbsnzjpbi7utijcltosqemad.onion

Tor Project’s Test Servers

Here are some test servers for experimenting with Tor v3:

These enhancements and changes in Tor v3 represent a significant step forward in terms of security, privacy, and efficiency. The longer .onion addresses, while more complex, offer greater protection against impersonation and phishing attacks, contributing to a safer and more secure anonymous browsing experience.

  1. Tor Browser 7.5a9 Release Notes ↩

  2. Homebrew Installation ↩

  3. Tor Project Wiki - NextGen Onions ↩

  4. Tor Specification - rend-spec-v3.txt ↩

  5. Wikipedia - Rendezvous Protocol ↩