Em.. "off-the-shelf OCR" sounds neat, but anyone who knows such words isn't an average spammer. The goal of basic SVG puzzles is to block 99% of the spammers who just type dumb comments on keyboards. The rest 1% can be taken care of by human mods.
TBH, I don't like the reCAPTCHA-like solutions. They are just annoying from my personal experience and if they rely on any 3rd party service, I'll give them a hard pass for this reason alone. My approach is to use trivial SVG-style captchas with adjustable complexity, e.g. instead of asking "23+34", we can ask "log(32)/log(2)" and effectively filter out everyone except people familiar with math, or "md5(2615), first 7 hex digits" and let in only people familiar with cryptography. Forcing users to detect birds and crosswalks will just make them upset, IMHO.
The puzzle will be sent as an SVG, obviously.
Em.. "off-the-shelf OCR" sounds neat, but anyone who knows such words isn't an average spammer. The goal of basic SVG puzzles is to block 99% of the spammers who just type dumb comments on keyboards. The rest 1% can be taken care of by human mods.
TBH, I don't like the reCAPTCHA-like solutions. They are just annoying from my personal experience and if they rely on any 3rd party service, I'll give them a hard pass for this reason alone. My approach is to use trivial SVG-style captchas with adjustable complexity, e.g. instead of asking "23+34", we can ask "log(32)/log(2)" and effectively filter out everyone except people familiar with math, or "md5(2615), first 7 hex digits" and let in only people familiar with cryptography. Forcing users to detect birds and crosswalks will just make them upset, IMHO.