Decaptcha defeats CAPTCHAs

One of the most annoying technologies ever created by the internet – the CAPTCHA has finally been defeated by an automated solution. Some scientists have come up with a program that is capable of overcoming the verification method used by online services everywhere to prevent automated sign ups and spamming done by computer bots.

Called Decaptcha, uses a two-phase audio CAPTCHA solver that successfully breaks the human test with 49-89% success rate on websites like eBay, Yahoo!, Digg, Authorize.net and even Microsoft’s Live.com. How does it work? Well, it gets the audio file that’s used in the CAPTCHA, removes the background noise and analyzes the spoken characters to figure out the correct letters.

In their tests, Decaptcha was able to solve the CAPTCHA puzzle at least once in every hundred attempts, which makes it the perfect solution for botmasters with a large army of compromised computers to utilize for their malicious intents. So far, Decaptcha can work with most CAPTCHA solutions out there, with one of the exceptions being Google’s recaptcha.net. It makes use of a different kind of audio which Decaptcha has yet to overcome.

If botmasters get their hands on Decaptcha, expect to see a surge in spam email accounts and forum posters once again. Read the full report on Decaptcha (PDF).

[Image Credit]

George Wong
Categories: Web
Tags: internet