Full Disclosure mailing list archives
Re: Attack & Defence Against Visual CAPTCHA
From: Feher Tamas <etomcat () freemail hu>
Date: Sat, 19 Mar 2005 21:45:48 +0100 (CET)
Hello, Let me chime in on the topic. Visual Captchas are useless 1., No matter how good they are, people will still solve them (you know the usual spammer trick: set up a free pr0n website and require visitors to solve the proxied captchas to access those adult pictures). 2., Visual CAPTCHAS alone cannot be used due to legal reasons (especially in Europe, where strong laws protect people with disabilties). You also need to provide an alternative (usually voice-based) method to let blind guys access the services or you get sued for discrimination. And this helps spammers, because this way they can avoid any complicated images you plan to generate. As you know, secret services of the world spent the better part of Cold War wiretapping as many phone lines as they could. There must be some extremely advanced software that can process speech without human assistance. Spammers have huge piles of money and they will bribe someone to give them the high tech, just like the russkies bought US state secrets from A. Ames et al. Don't spend too much time on inventing distored images of digit and alphabet strings. Regards, Tamas Feher. _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
Current thread:
- Attack & Defence Against Visual CAPTCHA Debasis Mohanty (Mar 19)
- <Possible follow-ups>
- Re: Attack & Defence Against Visual CAPTCHA Feher Tamas (Mar 19)