A complicated calculus-based anti-spam CAPTCHA

Graham Cluley
@gcluley

Eggheads at the Ruđer Bošković Institute in Zagreb, Croatia, are having some geeky fun with their web forms.

If you want to login to the institute’s Quantum Random Bit Generator service, you will be asked the usual questions like your username and password, but then you’ll be faced by a mathematical problem that may give you a nighmarish memories of your schooldays doing advanced calculus.

Hmm.. it’s a bit more complicated than the typical sort of CAPTCHA used by websites around the world to try to block spam bots and automated systems:

Sometimes, of course, these randomly-generated CAPTCHAs can go very wrong – potentially causing unintended offense to some amusement.

Somehow I don’t think the calculus-based CAPTCHA is going to catch on with the general public…

Read more in my article on the Naked Security website.

Found this article interesting? Follow Graham Cluley on Twitter to read more of the exclusive content we post.


Graham Cluley is a veteran of the anti-virus industry having worked for a number of security companies since the early 1990s when he wrote the first ever version of Dr Solomon's Anti-Virus Toolkit for Windows. Now an independent security analyst, he regularly makes media appearances and is an international public speaker on the topic of computer security, hackers, and online privacy. Follow him on Twitter at @gcluley, or drop him an email.

What do you think? Leave a comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.