Google has updated its reCaptcha platform with advanced authentication powers to help prevent increasingly sophisticated software bots from getting past its defences.
ReCaptcha is a web authentication tool designed to force web users to prove they are a person rather than a software bot by asking the user to enter the letters displayed in a distorted panel. It is used by numerous sites to try and stop spam bots creating millions of fake accounts.
Vinay Shet, Google product manager for reCaptcha, announced the update in a post on Google's Blog, explaining the new features are based on research about how humans behave online in order to try and improve the tool's performance.
"The reCaptcha team has been performing extensive research and making steady improvements to learn how to better protect users from attackers. As a result, reCaptcha is now more adaptive and better-equipped to distinguish legitimate users from automated software," he wrote.
Shet said the new reCaptcha platform will add numeric elements and constant monitoring to the traditional text-based solution to make it even better at spotting automated bots (an example is below).
"The updated system uses advanced risk analysis techniques, actively considering the user's entire engagement with the Captcha - before, during and after they interact with it. That means that today the distorted letters serve less as a test of humanity and more as a medium of engagement to elicit a broad range of cues that characterise humans and bots," he said.
Use of numbers should stop even the most advanced bot faking its way through the test.
"Humans find numeric Captchas significantly easier to solve than those containing arbitrary text and achieve nearly perfect pass rates on them," Shet claimed. "So with our new system, you'll encounter Captchas that are a breeze to solve. Bots, however, won't even see them."
Bot machines and programmes have been a growing problem facing the security community. The bot machines are usually owned by criminal groups and are part of a wider botnet of enslaved systems. The botnets have been used by organised criminal groups for a variety of purposes, including click fraud and Bitcoin mining.