Tor 0.4.8 arrives with security, performance improvements and more


Tor is a project whose main objective is the development of an anonymous communications network at the network level.

Announced the launch of the new version of Tor 0.4.8, in which several have been implemented Important features and bug fixes. This new release is positioned as the first stable version of the 0.4.x branch, which will be maintained as part of the regular maintenance cycle.

In this new branch of "Tor 0.4.8" updates will be discontinued after 9 months or 3 months after the release of the 0.4.9.x branch.

Main new features of Tor 0.4.8

In this new version of Tor 0.4.8 that is presented, one of its main novelties is the New method added, which has the function, protect Onion services from DoS attacks based on the use of proof of work (PoW) to identify customers whose requests should be processed first. The proof-of-work mechanism is intended to discourage attackers by making large-scale attacks costly and impractical, while giving priority to legitimate traffic.

It is mentioned that the defense Tor's PoW is a dynamic and reactive mechanism, which remains idle under normal usage conditions to ensure a seamless user experience, but when an onion service is under stress, the mechanism will request incoming client connections to perform a series of successively more complex operations. The service will then prioritize these connections based on the level of effort demonstrated by the client.

Another change that stands out in the new version is that the Conflux traffic separation protocol was implemented, allows you to increase the performance and reliability of the connections by splitting the traffic towards the exit node into two flows that pass through different chains of nodes. How the protocol works is based on the selection of pairs of confluence strings from a pre-designed pool, after which a rollback is performed to use regular strings. To increase performance, the data sent from the exit node is multiplexed and distributed over two channels, while the client also has the opportunity to transfer the connection to a delay reduction mode, in which a channel with delays is selected minimums for the data.

In addition to this, in Tor 0.4.8 the correct interaction of Tor directory servers (Directory Authority) and relays with directory servers that have changed their IP address is guaranteed. Previously, nodes continued to send data to the old address specified in the configuration file, even after the address change appeared in the network status list.

Of the other changes that stand out from this new version:

  • Added protection against DoS attacks on partially open channels and known broadcasts.
  • OpenSSL 1.1 APIs are now used for LibreSSL, fixing LibreSSL 3.5
  • Fixed compiler warnings on equix and hashx when compiling with clang.
  • The ClientUseIPv6 setting has been enabled, allowing the client to select relays with IPv6 addresses by default.
    fixed a very rare buffer overflow in hashx, specific to dynamics
    compiler on aarch64 platforms
    Processes with Pluggable Transport implementation are automatically restarted after completion.

Finally if you are interested in knowing more about it about this new version, you can check the details in the following link.

How to get Tor 0.4.8?

In order to get this new version, just go to the official website of the project and in its download section we can obtain the source code for its compilation. You can get the source code from the following link

While for the special case of Arch Linux users we can obtain it from the AUR repository. Only at the moment the package has not been updated, you can monitor it from the following link and as soon as it is available you can perform the installation by typing the following command:

yay -S tor-git

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