Almost all the developers working on web applications would have come across captcha or re-captcha.
And developers might have also used them on the web pages before authentication of users on web applications or before showing specific content to users.
As developers, we might have got a thought like how will this work behind the scenes, but in most of the cases, we developers would have ignored and went on configuring and using captcha.
In this article, we see a bit of behind the scene possibilities that a captcha might do.
After reading a bit about the history of captcha, I found that in the early days of the web people used the Leet method, to identify if website users are real people or robots (Leet is a kind of interpreting letters or words or numbers to a format which can be easily identified by robots, so that people can identify them).
During the 90s, search engines used such a Leet method to index the web pages, so that robots can be avoided and people can do indexing with Leet check.
In 2009, Google bought reCaptcha from the developer Luis von Ahn.
And nowadays almost all the web applications use the captcha or recaptcha. CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) has now become one of the security measures for web applications.
There are many kinds of captchas available nowadays ranging from simple checkbox, visual identifications, solving the math and also the audio for visually impaired people.
If we see the behavior of the Captcha on the web applications, when users input the checkbox or solve the challenge, Captcha doesn’t only read the user input and validate it in the backend, it really does something more as well, like
- It could be reading the user cursor actions.
- Challenges solved by the users would be some data which is needed by some other external applications or such solved data is needed for other external applications.
- There could be some AI algorithms which would capture the users input of the challenges or solutions and improvise itself for the next challenge or questions it puts up.
- And many more.
Actually, If you see carefully, a Robot is smartly checking whether the user is a robot or real people and that Robot is improvising itself to be more efficient in validating.