Quote from: nullius on December 25, 2017, 07:55:45 AM

Quote from: Vod on December 25, 2017, 07:20:50 AM

I think Theymos should replace the captcha with a proof of work challenge such as https://coinhive.com/

Reduce Spam AND make the forum some additional money.

This would (0) require Javascript (as reCAPTCHA doesbut worse, IIRC this also requires asm.js/webasm which I disable even when enabling JS), and (1) have a drastically disparate impact on those using fast computers versus slow computers/netbooks/mobile devices. It is also questionable whether it would answer the threat being staved off by the CAPTCHA. Admittedly, it would work better against what I suspect the threat to be, rather than against spam.

Vod, do you know the actual purpose of the CAPTCHA? Everybody seems to assume that its there to keep out spambots.[1] My first hunch is that theymos has a problem with bruteforcing of luser passwords, resulting in stolen accounts. You may perhaps know for certain, not as a matter of assumptions or speculation.

I would understand if theymos desires that such information not be disclosed. But I ask because I have wanted to suggest some alternative solutions; and its difficult to know whether my ideas are even worth mentioning.

1. This common assumption simply does not make sense to me. An account farmer could easily use human labour (self or others) to log bots into a large numbers of accounts with stay logged in checked, then let them stay logged in to make unlimited spam/nonsense/copypaste posts. It would be trivial; all the bots would need to do is to keep their cookies. I know this because I myself now stay logged in, on a credential apparently set to expire in the year 2023. I have not filled out the CAPTCHA since 10 December. Whereas a password bruteforcer would indeed be stymied by the CAPTCHA. A bruteforcer would also be slowed down by a POW. A spambot could complete the POW once, then stay logged in for years or until permabanned.

Forums can use the two and the members could select which option they like to log with it.
I remember such feature was used in faucets years ago.