[BCAB] Sound Captchas have just gotten harder

Paul David, the Wonder of Wembley p.balster at ntlworld.com
Mon Jun 25 15:21:34 BST 2012


>From Tom Lorimer

Hi Guys,

I recently tried to enter an online competition which used a Captcha in the 
entry form.

I normally use Firefox and Webvisum to solve Captchas, but as I was using 
IE8 at the time, I decided to use the Sound Captcha option. Normally you get 
away with entering 3 or 4 words, but no matter how often I tried, I kept 
getting an error message telling me my answer was wrong and togo back and 
try again. Anyway, after about a dozen tries I ended up solving the Captcha 
with Webvisum.

I contacted the company who were running the competition and they told me 
that it was Google who run the Captcha and that they couldn't do anything to 
help.

After a bit searching, I found out that Hackers had managed to crack the 
sound Captcha with a 99 percent accuracy. So to block the Hacking, Google 
have changed the way Sound Captchas are recorded and instead of only having 
to enter 6 words to solve the Captcha, it has now been increased to 12. I 
was never able to hear 6 words, and had to listen to the Sound Captcha over 
and over again before I got it right. How the hell do Google expect blind 
people to remember 12 words is beyond
me. Even having a recording device handy, I doubt if anybody could take down 
all these words with all that background noise. Here's the link to a page 
which explains what happened.

http://arstechnica.com/security/2012/05/google-recaptcha-brought-to-its-knees/

Tom 





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