CAPTCHA Definition: Completely Automated Public Turing test to tell Computers and Humans Apart. It is a security measure to distinguish between human users and bots.
Purpose: Protect websites from automated attacks like spam, fake accounts, and data theft.
Origin: Introduced in the early 2000s due to increasing bot activity. The first patent was filed in 2003 by Luis von Ahn and his team.
How it works: Presents challenges that are easy for humans but difficult for computers, such as identifying distorted text or specific objects in images. Based on the Turing Test.
Evolution: Started with distorted text, evolved to include image recognition, audio challenges, and behavioral analysis (e.g., mouse movements with “Invisible reCAPTCHA”). reCAPTCHA was introduced in 2009 to digitise printed text.
Applications: Used in website forms, comment sections, registration pages, financial transactions, account recovery, and online surveys.
Limitations: Can be bypassed by increasingly sophisticated bots. Presents accessibility challenges for users with disabilities. Can be annoying and time-consuming for users.
Future: Needs to become more accessible and user-friendly while remaining effective against evolving bot technology.
