logoalt Hacker News

drum55yesterday at 3:20 PM5 repliesview on HN

Which is trivially bypassed by an actual implementation of the proof of work in non-javascript, rendering it absolutely useless. The website is approximately 3800x times slower than native code, and hundreds of thousands of times slower than the CUDA kernel claude wrote. The "proof of work" is just non existent at that point, they're solved in milliseconds for what would take the browser version 10 minutes or more, it's security by obscurity being dressed up as something more.

  pow_server  http://127.0.0.1:8080   backend avx512-x16
  ──────────────────────────────────────────────────────────
  uptime   00:03:12
  solver   ● BUSY  difficulty 9, 0.3s
  queue    [####################............] 5/8   peak 12
  ──────────────────────────────────────────────────────────
  accepted 1240        solved 1180
  503 shed 48      504 timeout 2      4xx/5xx 10
  ──────────────────────────────────────────────────────────
  last     difficulty 5  nonce 645376  in 9 ms  (101.6MH/s, avx512-x16)
  hashes   3.90GH total   avg 65.3MH/s
  Ctrl-C to stop
Claude even made a nice little API server for it after implementing midstate compression, AVX multi way hashing, and a CUDA kernel. This doesn't stop the literal LLM it's trying to block from solving the challenges, it's really annoying that everybody is using it and claiming that it's something that's usable in the real world as a result of it using proof of work. It's obscure, and obscure is fine so long as nobody is pretending that it is secure.

Replies

harshrealityyesterday at 3:26 PM

It is not absolutely useless, empirically, which you'd discover if you had a website getting hammered by bots and experimented with anubis as a countermeasure.

While dedicated scrapers/attackers could work around it, and they could do so much more efficiently than the client-side js, almost none of them do. Unless you like paying additional hosting resource fees to serve bots, it's a worthwhile option, and is less annoying to typical human visitors than cloudflare's interactive captcha/challenge which is what most people use.

The main author is aware that the algorithm is far from ideal for this purpose. See https://news.ycombinator.com/item?id=48869064 . If more bots start to answer the primitive challenge anubis uses now, that'll hasten implementation of a different algorithm.

Don't let the perfect be the enemy of the good enough. For now, the algorithm or challenge scheme almost doesn't matter. Since it's much smaller-scale than cloudflare's challenges, that's probably why very few scrapers and botnets bother to solve anubis's trivial sha2 pow.

Targeted attacks may not be repelled at all. That's not the point.

show 1 reply
inigyouyesterday at 3:26 PM

But the people you're defending against don't do that.

They also don't load CSS but for some reason the security theater PoW won the mindshare.

show 2 replies
rokkamokkayesterday at 4:23 PM

Like any lock, it's mainly to deter less determined adversaries (which account for the vast majority)

Galanweyesterday at 3:26 PM

The point of PoW access is not that its hard to bypass, it's that you cannot bypass it at scale.

show 2 replies
gum_wobbleyesterday at 3:24 PM

how so, can you link to any sources?

show 1 reply