🧅 The new DoS attack protection feature with PoW has been enabled for Tor hidden services 🛡️🔒

The past 26 August, Tor introduced officially a proof-of-work (PoW) defense for onion services designed to prioritize verified network traffic as a deterrent against denial of service (DoS) attacks.

~ > This feature at the moment, is deactivate by default, so you need to follow these steps to activate this on a MiniBolt node:

• Make sure you have the latest version of Tor installed, at the time of writing this post, which is v0.4.8.6. Check your current version by typing

tor --version

Example of expected output:

Tor version 0.4.8.6.
This build of Tor is covered by the GNU General Public License (https://www.gnu.org/licenses/gpl-3.0.en.html)
Tor is running on Linux with Libevent 2.1.12-stable, OpenSSL 3.0.9, Zlib 1.2.13, Liblzma 5.4.1, Libzstd N/A and Glibc 2.36 as libc.
Tor compiled with GCC version 12.2.0

~ > If you have v0.4.8.X, you are OK, if not, type sudo apt update && sudo apt upgrade and confirm to update.

• Basic PoW support can be checked by running this command:

tor --list-modules

Expected output:

relay: yes
dirauth: yes
dircache: yes
pow: **yes**

~ > If you have pow: yes, you are OK

• Now go to the torrc file of your MiniBolt and add the parameter to enable PoW for each hidden service added

sudo nano /etc/tor/torrc

Example:

# Hidden Service BTC RPC Explorer
HiddenServiceDir /var/lib/tor/hidden_service_btcrpcexplorer/
HiddenServiceVersion 3
HiddenServicePoWDefensesEnabled 1
HiddenServicePort 80 127.0.0.1:3002

~ > Bitcoin Core and LND use the Tor control port to automatically create the hidden service, requiring no action from the user. We have submitted a feature request in the official GitHub repositories to explore the need for the integration of Tor's PoW defense into the automatic creation process of the hidden service. You can follow them at the following links:

• Bitcoin Core: https://github.com/lightningnetwork/lnd/issues/8002
• LND: https://github.com/bitcoin/bitcoin/issues/28499

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More info:

• https://blog.torproject.org/introducing-proof-of-work-defense-for-onion-services/
• https://gitlab.torproject.org/tpo/onion-services/onion-support/-/wikis/Documentation/PoW-FAQ

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Enjoy it MiniBolter! 💙