This is the basic misconception behind the Anubis design. In an anti-spam system, there's a user/abuser reward asymmetry. Users make single requests and get some constant reward V. Abusers make millions of requests and also get some constant reward V. Proof-of-work exploits the asymmetry: costs are, by a factor of ~millions, disproportionately imposed on abusers.
That's exactly not what happens with scrapers. Scrapers make millions of requests, yes. But each one of those requests produces an average (token-denominated) reward V'. There's no asymmetry at all: you're just adding a fixed cost to each reward, for both users and abusers.
That's before you even get to questions like "does the system actually work, or does a single solve get practically unbounded rewards".
> There's no asymmetry at all: you're just adding a fixed cost to each reward, for both users and abusers.
There is: users solve the PoW once, scrappers solve it every time they rotate IP addresses. Some of them change their IP address on every request, so they keep solving the PoW over and over.
That doesn't matter! Every time they successfully solve the challenge, they're getting the token reward. That's the missing asymmetry. In an anti-spam system, 99.999% of all transactions are unrewarded.
I suspect that's most of the value, and that the deterrent is about software construction and not about the proof-of-work, which I've been saying for the last year is a productive direction for Anubis to head towards. Instead, it's just sort of tormenting normal people, as a kind of performance of anger about AI.
Which: I get! If it's your site, perform all the anger you want.
I have a small personal site with an exposed Git repository. I'm getting crawled from about 100000 residential IPs from several ASNs (mostly in Brazil). Each crawler makes a couple of requests per minute.
OK, but that doesn't change anything. You have a large pool of IPs, each of which only needs to expend a handful of extra milliseconds of work to get unlimited access to the protected resource.
Even if you had to solve a L6 challenge for every request it's faster than the total RTT time of most servers. In other words not a meaningful barrier. And L6 is already a level which severely interferes with human usage of a site.
a $5000 ASIC-based device can hash SHA256 at 200TH/s or more.
This is the basic misconception behind the Anubis design. In an anti-spam system, there's a user/abuser reward asymmetry. Users make single requests and get some constant reward V. Abusers make millions of requests and also get some constant reward V. Proof-of-work exploits the asymmetry: costs are, by a factor of ~millions, disproportionately imposed on abusers.
That's exactly not what happens with scrapers. Scrapers make millions of requests, yes. But each one of those requests produces an average (token-denominated) reward V'. There's no asymmetry at all: you're just adding a fixed cost to each reward, for both users and abusers.
That's before you even get to questions like "does the system actually work, or does a single solve get practically unbounded rewards".
> There's no asymmetry at all: you're just adding a fixed cost to each reward, for both users and abusers.
There is: users solve the PoW once, scrappers solve it every time they rotate IP addresses. Some of them change their IP address on every request, so they keep solving the PoW over and over.
That doesn't matter! Every time they successfully solve the challenge, they're getting the token reward. That's the missing asymmetry. In an anti-spam system, 99.999% of all transactions are unrewarded.
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I wonder whether what Anubis is doing might be blocking agents that do not run JS or that have a timeout (or humans who give up as I just did)
I suspect that's most of the value, and that the deterrent is about software construction and not about the proof-of-work, which I've been saying for the last year is a productive direction for Anubis to head towards. Instead, it's just sort of tormenting normal people, as a kind of performance of anger about AI.
Which: I get! If it's your site, perform all the anger you want.
I have a small personal site with an exposed Git repository. I'm getting crawled from about 100000 residential IPs from several ASNs (mostly in Brazil). Each crawler makes a couple of requests per minute.
Anubis doesn't really help against this.
no, a single solve returns a token which entitles the scraper to access the site as much as it wants for one week.
The token should only be valid for one IP, so the scraper has to keep solving challenges if it rotates IPs.
OK, but that doesn't change anything. You have a large pool of IPs, each of which only needs to expend a handful of extra milliseconds of work to get unlimited access to the protected resource.
Even if you had to solve a L6 challenge for every request it's faster than the total RTT time of most servers. In other words not a meaningful barrier. And L6 is already a level which severely interferes with human usage of a site.
a $5000 ASIC-based device can hash SHA256 at 200TH/s or more.
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not if its running on someone else's device