CAPTCHA

News: CAPTCHA has made the internet a safer place today. But as bots keep getting smarter, CAPTCHA needs to figure out how to be more accessible and easier to use for humans in the world of digital security.

About CAPTCHA

• CAPTCHA stands for “Completely Automated Public Turing test to tell Computers and Humans Apart”.
• It is a programme that protects websites against bots by generating and grading tests that humans can pass but current computer programmes cannot.
• Developed by: Computer scientists Luis von Ahn, Manuel Blum, Nicholas J. Hopper, and John Langford filed the first patent for CAPTCHA in 2003.
• Working:
  • It works based on an idea called the Turing test, proposed by British mathematician Alan Turing back in the 1950s.
  • These tests involve recognising letters, numbers, or symbols that were deliberately messed up so that machines couldn’t parse them but humans could.
• Evolution of CAPTCHA;
  • reCAPTCHA:
    • As the bots became more advanced, a new advanced CAPTCHA resulted into reCAPTCHA in 2009.
    • It used words from scanned books to verify users.
    • It not only stopped bots from taking over, but it also helped digitise printed texts.
  • Invisible reCAPTCHA:
    • Introduced in 2014 by Google.
    • It used users’ mouse movements to tell if they were human.