Introduced in the early 2000s, CAPTCHAs have annoyed users for decades now.
But have you ever wondered how CAPTCHA work, and why websites force you to solve them?
What Is CAPTCHA?
CAPTCHA stands for Completely Automated Public Turing test to tell Computers and Humans Apart.
As the name suggests, it distinguishes between humans and computers.
The basic concept of CAPTCHA relies on the lack of computer intelligence to recognize patterns.
Humans, meanwhile, are hard-wired for generations to spot and identify patterns as a safety mechanism.
It represents a sequence of characters in an alienated form that’s a little difficult to interpret.
These include distortion, rotation, flipping, wobbliness, capitalization style, and overlapping with adjoining characters.
Audio CAPTCHA
Audio CAPTCHA serves as an alternative to text-based CAPTCHAs and caters to visually impaired users.
Again, there is distortion, this time in the form of added background noise.
An interesting thing to note is that the Python CAPTCHA module only works with numbers.
Image CAPTCHA
Image CAPTCHAs are an alternative to text-based image CAPTCHAs.
These are the typical CAPTCHAs you will tackle daily.
These CAPTCHAs ask you to identify a particular object such as a boat, truck, or fire hydrant.
They present these alongside other images to pick from.
These are much more human-friendly than text-based tests as well as more difficult for bots to recognize.
No CAPTCHA ReCAPTCHA
Google owns ReCAPTCHA which uses advanced risk analysis and adaptive challenges to prevent bots.
ReCAPTCHA retrieves content from Google Street View, newspapers, books, and more.
This is possible as it tracks the movements and identifies the click.
One thing to note is thatReCAPTCHA captures your private informationas well.
These are a few of the generated examples.
This is yet another fascinating design generated via the same program.
They help maintain the accuracy of online polls by preventing bots from flooding them with negative responses.
