It never really cohered as a solution. High-powered scrapers are better equipped to handle proof-of-work challenges than end users. Proof of work makes sense for a password hash, where any one guess at a password provides zero marginal utility. But every request from a scraper is productive to the scraper.
I disagree. The kernel finds it effective - 66% of scrapers are turned away directly.
The scraper problem now is fleets of residential proxy devices - often things like smart TVs, phones, and browsers with some “proxy SDK” installed as part of an app’s monetization scheme. They make a couple of requests to a site - just enough to fly under the radar - and move on to a different site.
If each new site they hit forces them to solve a proof-of-work, that’s a meaningful dent in their scraping performance. Many of these boxes may not even have the spare CPU power to efficiently solve so many proofs of work - and anything that makes an owner notice their device is running slow is something that could meaningfully impede adoption of these SDKs, or force the operators to choose between minimizing performance impact or scraping more sites.
The implication here is that the proxy fridge forwards the Anubis challenge to a dedicated rig controlled by the scraper who efficiently solves it and returns the answer.
It's weird to believe data center based, Internet-scale scraping operations will be less able to allocate compute to proof-of-work challenges than individual users. This is design problem with things like Anubis: proof-of-work depends on a cost asymmetry between attacker and defender. But in scraping, both legitimate users and scrapers get the same value out of a transaction.
https://news.ycombinator.com/item?id=44962529
It never really cohered as a solution. High-powered scrapers are better equipped to handle proof-of-work challenges than end users. Proof of work makes sense for a password hash, where any one guess at a password provides zero marginal utility. But every request from a scraper is productive to the scraper.
The scraper problem now is fleets of residential proxy devices - often things like smart TVs, phones, and browsers with some “proxy SDK” installed as part of an app’s monetization scheme. They make a couple of requests to a site - just enough to fly under the radar - and move on to a different site.
If each new site they hit forces them to solve a proof-of-work, that’s a meaningful dent in their scraping performance. Many of these boxes may not even have the spare CPU power to efficiently solve so many proofs of work - and anything that makes an owner notice their device is running slow is something that could meaningfully impede adoption of these SDKs, or force the operators to choose between minimizing performance impact or scraping more sites.