The bots can probably solve them easier than blind people anyway, or they can outsource them to third world workers for next to nothing. E.G. Anticaptcha [0]:
> Starting from 0.5USD per 1000 images, depending on your daily spending volume
The bots can probably solve them easier than blind people anyway, or they can outsource them to third world workers for next to nothing. E.G. Anticaptcha [0]:
> Starting from 0.5USD per 1000 images, depending on your daily spending volume
There are no "best" version of captcha. I've worked on several large scale projects where captcha was floated and then quickly abandoned in favor of other methods like Honeypot or using other methods to weed out bots and other 3rd party agents.
If you have to use captcha the least worst are probably reCaptcha V2 and hCaptcha for accessibility.
Even renting the compute on AWS, it only costs $0.01 per minute for the equivalent of a decent desktop computer (c8g.4xlarge). While an attacker will likely either use a botnet, or hardware better suited for solving the PoW than the hardware the user is using.
Though CAPTCHAs don't really work well anymore either, since solving services are quite cheap. Recaptcha is nowadays primarily based on other factors, like IP reputation, susceptibility to google tracking, and behavioral scoring.