CAPTCHA schemes still easy to bypass

[J65nko]

From http://h-online.com/-1371934

Security researchers at Stanford University have found that the vast majority of text-based anti-spam tests are easily bypassed. They cracked the CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) mechanisms of several popular web sites.

The researchers tested the query mechanisms of such sites as Google, eBay and Wikipedia. Only Google's CAPTCHA and the reCAPTCHA systems managed to withstand the attacks.

[DutchDaemon]

Wonder how KeyCaptcha performs (https://www.keycaptcha.com/).

[Virus]

Originally Posted by DutchDaemon

Wonder how KeyCaptcha performs

Quite good if you don't mind to cut your registrations by 95%
I can't give links, google by:

• "Registrations down by 95% - not one complaint" site:stopforumspam.com

I, for example, cannot register in forums or comment blogs with KeyCAPTCHA (I am on dynamic IP-address getting "We have detected spam activity, your actions are blocked")

One should also remember understand that by installing KeyCAPTCHA plugin a webmaster (owner) opens the backdoor for executing scripts in his visitors browsers loaded from KeyCAPTCHA.com backservers of professional spammers (with a long list of deceptive practices)

• google by "New Trends in Spamming: Spam Fused into Antispam Protection with Spamming Visitors Instead of Web Sites"

while a webmaster cannot control or even see what is being loaded to his visitors and a visitor cannot even reproduce it (they use for it various tricks like intermittent spamming, only on first couple of min of first visit, on 1st passing, geo-targeting, etc.)

[J65nko]

I don't understand that reCAPTCHA is not broken. If I enable this in the forum software for registration of new users, we get 25 to 50 spambot registrations daily.

EDIT: see vBulletin forums hit by reCAPTCHA cracking spam bot

[DutchDaemon]

Originally Posted by J65nko

I don't understand that reCAPTCHA is not broken. If I enable this in the forum software for registration of new users, we get 25 to 50 spambot registrations daily.

EDIT: see vBulletin forums hit by reCAPTCHA cracking spam bot

Same here, it is useless at the moment.

[DutchDaemon]

The keyCAPTCHA anti-campaign is based on one single dedicated detractor. Can't take that seriously, really.

[Carpetsmoker]

Best reason not to use KeyCAPTCHA:

You may experience KeyCAPTCHA below

Please install Adobe Flash plugin (version 9.0.115 or above) into Your browser, please go to this link for install Adobe Flash plugin

[DutchDaemon]

Have you tried the suggestions in the last paragraph of http://www.pcpro.co.uk/blogs/2011/01...king-spam-bot/, i.e. turning on Q&A? This may be vB 4+ only.

[J65nko]

Yes, we turned on Q&A. Now we only get 3 to 4 SEO spam registrations a day.