Security News > 2023 > August > Bots Are Better than Humans at Solving CAPTCHAs

Abstract: For nearly two decades, CAPTCHAS have been widely used as a means of protection against bots.

Throughout the years, as their use grew, techniques to defeat or bypass CAPTCHAS have continued to improve.

CAPTCHAS have also evolved in terms of sophistication and diversity, becoming increasingly difficult to solve for both bots and humans.

In this work, we explore CAPTCHAS in the wild by evaluating users' solving performance and perceptions of unmodified currently-deployed CAPTCHAS. We obtain this data through manual inspection of popular websites and user studies in which 1, 400 participants collectively solved 14, 000 CAPTCHAS. Results show significant differences between the most popular types of CAPTCHAS: surprisingly, solving time and user perception are not always correlated.

We performed a comparative study to investigate the effect of experimental context specifically the difference between solving CAPTCHAS directly versus solving them as part of a more natural task, such as account creation.

Whilst there were several potential confounding factors, our results show that experimental context could have an impact on this task, and must be taken into account in future CAPTCHA studies.

News URL

https://www.schneier.com/blog/archives/2023/08/bots-are-better-than-humans-at-solving-captchas.html