The most interesting invention
You have all probably seen these while surfing the web, but do you know the purpose of it and how exactly it verifies whether or not you’re a robot?
This is called a CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart). They were invented in 2003 by researchers at Carnegie Mellon University in order to be used as a security check on websites to ensure only human users can pass through.
Only humans can read this text, computers can’t!
So now millions of captchas are being solved every single day, isn’t there a way that all this brain power can be put to good use? YES, there is. The creators of ReCaptcha started scanning books and converting them into PDFs using software, any words that were too hard for the computer to convert they would put into a captcha and let a human convert them.
At this point 100 million ReCaptchas were being solved every day, the equivalent of 2.5 million books a year. So Google says “let’s buy ReCaptcha” and they did in 2009. Google digitized all of google books and all of the New York times archives. When they ran out of books to digitize Google started giving people street numbers from Google street view to help Google maps.
Everything was going great, until… computer technology started getting advanced enough to solve captchas on its own. They started making captchas harder to solve, but eventually the technology caught on and Google needed a new strategy.
So Google engineers came up with the captcha that we all know and love!
When you click the checkbox, it sends over an HTTP request to Google with information like your IP address, your location and time, the way you move your cursor before you click, how you were scrolling the page, time intervals, and more. Most of the time the machine learning bots over at Google can tell whether or not you are a robot, but if they’re still unsure you get something like this-
And that’s how Google can tell who’s a human and who isn’t. pretty cool, huh?