Google's new CAPTCHA knows you're human (not a robot)

摘要

Google has launched an easier system for proving you're a real person when signing into websites, letting you do so without clicking anything on screen. Websites use CAPTCHA systems to stop automated software (known as 'bots') posting spam, writing abusive content, and stealing email addresses and passwords. But they've also been a headache for people to use, in particular the early CAPTCHAs that forced you to decipher squiggly letters and numbers. While they were sufficiently hard for bots to understand, they were also often too difficult for many people to work out.