23 June 2023

How Does the Internet Know You're Not a Robot?

If you've used the Internet for any length of time, you've probably run into one of those annoying CAPTCHA tests when you try to sign into a site. It may be surprising to learn, but CAPTCHA isn't just a cute name concocted by a soulless tech marketers, but an acronym. It stands for "Completely Automated Public Turing test to tell Computers and Humans Apart". So it's also a really bad acronym on top of being a cute name concocted by a soulless tech marketers.

A lot of these involve pattern recognition or puzzle solving, but there's also that one that asks you to check a box beside the words "I'm not a robot". How on earth can that kind of CAPTCHA test tell you apart from a malicious bot programmed to impersonate you as it tries to access your online accounts?

The answer can be found in the following two-minute clip from QI, a BBC panel comedy show hosted by Sandi Toksvig in an episode featuring Alan Davies, Maisie Adam, David Mitchell and Holly Walsh.

And there you have it! That also explains why you might get blocked from a site after you've mistyped your 8-15 character password containing lower case, upper case, numeric and special characters several times in a short period of time. You haven't just failed to remember it or to type it correctly, you've flunked the CAPTCHA test that tells the system you're not a malicious bot!