And CAPTCHAs based on reading text — or other visual tasks — prevent blind or visually impaired users from accessing the protected resource.
With reCAPTCHA, Google is trying to ease the CAPTCHA procedure by introducing an undetectable new system, which uses algorithm to determine whether you're human or bot.
While this isn't the Internet giant's first attempt to ease the user identification procedure, as it had earlier introduced "No CAPTCHA reCAPTCHA", a system that only requires a user to tick a box next to "I'm not a robot."
No CAPTCHA reCAPTCHA in contrast to the CAPTCHA system that tasks users with solving a puzzle or typing a word, employs Google's Advanced Risk Analysis engine that "actively considers a user's entire engagement with the CAPTCHA - before, during and after - to determine whether that user is a human."
reCAPTCHA was originally developed by Luis von Ahn, Ben Maurer, Colin McMillen, David Abraham and Manuel Blum at Carnegie Mellon University's main Pittsburgh campus and was acquired by Google.
If you're interested in using Invisible reCAPTCHA for your web-based resource, you can sign up on the Google reCAPTCHA website.