Google moves on from CAPTCHA

Google has developed a new system for checking that web users are humans and not robots, which ditches CAPTCHA puzzles in favour of behavioural analysis. CAPTCHAs are difficult for automated systems to solve, but easy for humans, so they’re used by sites such as ticket vendors to stop bots buying in bulk. They show skewed words, or a series of pictures that, for example, ask you to type the words or numbers that appear, or click all the images containing tea or some other theme. Instead, the new system observes how you interact with a site, looking for ‘imperfect’ human behaviour, such as the length of time taken to perform actions and how a mouse is moved, which will differ from the movements of an efficient, automated robot.

How will it affect you?

Most of us find CAPTCHAs annoying because they add an extra step to processes such as online purchases and registering with a site, and some people – particularly those with sight problems – struggle to make out the wobbly text or small, poor-quality images, although including an audio aspect can make this easier.

That said, CAPTCHA systems have a side benefit: they’ve been used to help digitise books and to teach artificial intelligence. Words that computers couldn’t automatically read were fed through CAPTCHA, letting us humans type the text, while AI systems were trained using picture CAPTCHAs. Simplifying the system will sacrifice those benefits.

What do we think?

Tackling the automated abuse of online systems is a constant battle, so it’s no surprise that CAPTCHA is the latest casualty in the search for a simpler, better system. That said, it’s hard to believe bot makers won’t simply programme their scripts to interact with websites in a way that mimics human behaviour. Most likely, this is just the next stage in a system that evolves by two sides constantly trying to outwit each other.