As a lot of people here should be aware of, intro cell DDoS attacks are a thing that has been around for many, many years. I assume this post from 2020 is addressing it, as the description sounds much like it.
To this very day, in Q3 of 2026, a default hidden service can be taken offline with the power of a single toaster. It doesn’t even have to be a distributed attack at all, nor does it need any noteworthy computing power on a single device.
If you, as a hidden service operator, do basic research, find the PoW params, and configure them, your Tor service still honors intro cells with PoW=0 instead of discarding them, with no option to even just optionally disable that. Criminals had to do the work as part of the EndGame release (min-work patch), requiring you to manually compile Tor just to have a very basic protection.
It’s still not hard to shut down a service with PoW. One would think using onionbalance solves this, but onionbalance leaves you with zero PoW protection at all again because you didn’t make it compatible with it. It’s a distribution of unprotected frontends. See previous points about how much it takes for a single Tor service without PoW to be taken down. It’s a bit different for onionbalance fronts, but the point comes across.
Distributed PoW can be done though. This is what the major criminal sites, where DDoS is an omnipresent topic, are doing and starting to do more.
What needs to happen for the Tor Project to finally address this? Should I release the tool for this so we see perhaps a majority of the network disappear? How much are whistleblower/GlobaLeaks, dissident, and other sites worth if they would all be down? You market Tor as a tool for those (in reality, we all know it’s barely used like this), but unless you have deep knowledge and enough financial resources, whatever valuable information you would be publishing on the site will simply not be available to anyone given that, by definition, there will be actors who want the information gone.
The only reason for Tor to appear anyhow functional to most is that no tool appears to have been made public yet in all the years. I wouldn’t be aware of it at least. I’m very confident it would be highly chaotic, while you had over half a decade to get a solution out in calm with no real pressure.
Are there any on-going efforts or you called it a day?