The Evolution of Captcha

Evolution of Captcha


For over a decade, Captchas have been used to distinguish a human from a computer. The public Turing Test has remained relatively unchanged from its inception. Traitionally, Captchas required the user to reenter distorted numbers or letters to prove they are not a bot. Now, Google has launched the invisible reCaptcha, which is self explanatory in its concept. It may appear as though this redesign simply removes a nuisance but the reCaptcha serves a larger purpose.

History of Captcha

Captcha remains a backronym for Completely Automated Public Turing Test to tell computers and humans apart. Though these tests serve more of a purpose than denying bots entery to a website, which does costs advertisers, on a whole, billions yearly. In 1997, Captcha was created  to prevent bots from adding URLs to a search engine. It relied on the ability of the user to complete an easy task that is difficult for a computer. For example, the distorted text presented in a Captcha is difficult for machines to decipher. For this reason, captchas also serve as a benchmark test for artificial intelligence. Computers that can solve Captchas are assumingly able to solves hard unsolved AI problems.

The Invisible Captcha

In 2008, Luis von Ahn, who also founded Duolingo, reimagined the Captcha. Google bought this “reCaptcha” a year later. The present version of the reCaptcha is boasted as “invisible”. Still, the invisible Captcha operates under a veil of secrecy. Though we know it works in the background and interprets variables such as your cursor movement to determine your validity.

This invisible reCaptcha will spare internet users from the traditional and often annoying authorization process. Aside from save a few seconds for web friendly humans; the invisible reCaptcha presents a more difficult problem for the machines that try to crack it in an effort to further artificial intelligence.