3 ms·
I wouldn't consider it invulnerable to OCR, considering the fact that only half of the captcha is actually doing validation -- the other half is digitization.
by Shank 13y ago
I wouldn't consider it invulnerable to OCR, considering the fact that only half of the captcha is actually doing validation -- the other half is digitization.
Plus, statistically a few groups have worked to break it in the past[1]. Even without breaking it programatically, buying human labor to solve them is sometimes equal or less expensive[2].
[1]: http://arstechnica.com/security/2012/05/google-recaptcha-brought-to-its-knees/ http://arstechnica.com/security/2012/05/google-recaptcha-bro...
[2]: http://www.npr.org/templates/story/story.php?storyId=130594039 http://www.npr.org/templates/story/story.php?storyId=1305940...
- codeflo 13y agoSo what if half of reCAPTCHA is not a captcha? You still need to break the other half.
- meowface 13y agoYou're right that captcha farms (human labor, usually close to slave labor) allow spammers a fairly cheap method of bypassing them, but they're fairly slow (unlike OCR), not necessarily that accurate themselves, and increases the barrier required to spam. If a spammer expects to personally make $4 per 1000 advertisements posted, and if 1000 captchas costs $1, that's a massive profit loss for them. At least from my experience, setting up reCAPTCHA on personal sites reduces spam to 0. They'll usually only spend money on captcha farms for sites that garner huge amounts of traffic, leaving smaller sites in the clear.