Google's Replacing ReCAPTCHA Tests with 'Invisible ReCAPTCHA'

If you’ve ever submitted a form on the internet (and who hasn’t?), chances are you’ve had to transcribe a series of blurry letters and digits to a blank box. It’s a form of challenge-response testing called CAPTCHAs (Completely Automated Public Turing test to tell Computers and Humans Apart), and it’s designed to prevent clever ‘bots from hammering websites with nonsense data. One of the most widely adopted forms is Google’s reCAPTCHA, which displays as many as 100 million tests every day. But starting on Thursday, the search giant is getting rid of ’em.

Google is introducing “invisible reCAPTCHAs,” or CAPTCHAs that automatically disappear when a human user is detected. Form fillers that trip Google’s Advanced Risk Analysis algorithms will still have to solve the CAPTCHA test, but most users won’t see it at all.

That’s apparently thanks to “advanced analysis techniques” that consider a user’s “entire engagement” with CAPTCHA and “evaluate a broad range of cues.” It’s more than a one-time deal — Google says it “actively consider[s] a user’s engagement with the CAPTCHA — before, during, and after — to determine whether that user is a human.”

Google acquired reCAPTCHA from a team at Carnegie Mellon University’s main Pittsburgh campus, and since then, it has made it free. That has helped it grow into one of the most widely used CAPTCHA providers in the world, and the anti-spam test of choice for Facebook, TicketMaster, Twitter, 4chan, CNN.com, StumbleUpon, Craigslist, and tens of thousands of others.

Google has used the results of reCAPTCHAs for social good. As part of the project, it has digitized more than 13 million articles from The New York Times dating from 1851 to the present day, and transcribed tomes too illegible to be scanned by computers. The results of reCAPTCHA tests have helped to translate books into different languages, verified the characters of street addresses in Google’s Street View mapping service, and supplied researchers with data for “next-generation Artificial Intelligence.”

In 2014, Google began to replace the reCAPTCHA system with a simpler alternative called No CAPTCHA ReCAPTCHA: A checkbox saying “I’m not a robot.” Using a system of clues such as cookies — small pieces of data sent from a website and stored on a user’s computer by the user’s web browser — and mouse movements, the improved reCAPTCHA was able to distinguish non-human users from ‘bots almost instantaneously.

Now, reCAPTCHA won’t even ask you to lift a finger. And that’s probably a good thing — a researcher recently demonstrated a flaw that taps Google’s own services to bypass reCAPTCHA’s encryption.