This blog is retired.

Archive for the ‘CAPTCHAs’ Category

Yahoo CAPTCHA is broken

Tuesday, January 22nd, 2008

According to the hmm… press-release (formally, it’s a blog entry, but the style is very press-releasish), the Yahoo CAPTCHA is broken.



The best CAPTCHA ever - 2

Monday, January 14th, 2008

I already wrote about The best CAPTCHA ever — it’s a simple, but impressive looking math expression. Use of a scientific CAPTCHA is taking off. Now you can see one on the registration page of the library of Moscow Institute of Physics and Technology:

circuit captcha



W3C has had it with CAPTCHA

Wednesday, December 12th, 2007

You’ve probably heard of the World Wide Web Consortium (W3C); it’s is an “international consortium where member organizations, a full-time staff, and the public work together to develop Web standards.

According to their web site, their mission is:

“To lead the World Wide Web to its full potential by developing protocols and guidelines that ensure long-term growth for the Web.”

Well, lately they have been working hard to lead the web away from CAPTCHA, and with good reason. According to this article on their web site, CAPTCHA is giving webmasters a “false sense of security.”


How to Give Your Hard Work Away For Free

Wednesday, November 7th, 2007

Good job! You’ve built a great web site that’s going to attract a lot of visitors. But before you start counting all of that money you plan to make, take a moment to meet Mr. FUD.

Yep, good old Fear, Uncertainty, and Doubt is about to step into your life if you’re thinking about adding a CAPTCHA gateway to your registration or message forms. Here are two reasons why:


OK, here’s a cool CAPTCHA tool I can actually get behind

Wednesday, September 5th, 2007

Every now and then a smart anti-SPAM solution comes along that’s actually worth taking a close look at. ReCAPTCHA™ is one of those tools.

Everyone who reads my blog already knows that standard CAPTCHA utilities have been hacked. And you already know that the best form-based anti-SPAM tools require a modicum of human intelligence to unlock the comments form and allow a comment to be posted.

And that’s why I’m so excited about ReCAPTCHA. Not only is it human intelligence-based, but it’s free as well. And to make it even better, if you use ReCAPTCHA, you’ll actually be helping to spread literacy around the world.

Here’s how it works:


Hot captcha, or CAPTCHA with fun

Sunday, September 2nd, 2007

CAPTCHA or not CAPCTHA… Any anti-spam protection disturbs your visitors. But folks at found a nice trick to compensate the irritating proof-you-are-a-human step. What they do?


Captcha recognition experiment

Wednesday, August 29th, 2007

Just stumbled upon the article “Using AI to beat CAPTCHA and post comment spam”. There is a number of projects related to breaking CAPTCHAs and a number of articles on the topic, but this article strikes me most, because of:



Sunday, August 26th, 2007

Recently I analyzed section “PHP :: Scripts and Programs :: Security Systems”. Looking through the all 9 pages, I identified 5 categories:

* crawler protection,
* login, users, groups, roles, rights, authentification,
* data encryption,
* PHP and HTML source code encryption.

As one expects, the biggest category is “CAPTCHAs”. But how to select the best one?


Craziest Captchas on the Web

Wednesday, August 22nd, 2007

I already wrote about the CAPTCHA I like most. Just to repeat, here it is:
mathematical captcha
Recently I found a very nice collection, don’t miss it: Craziest Captchas on the Web.

CAPTCHA: The Broken Token

Wednesday, August 15th, 2007

CAPTCHA has been broken. Not just once, but over and over again. In fact, do a search for “CAPTCHA breaker” or “CAPTCHA hack” and you’ll find plenty of web sites that are all too happy to tell spammers how to get around the image tokens that CAPTCHA scripts use to try to keep unwanted people out.