Ads Captcha

Jonathan Wilkins took a look at Google new Captchas and found them easy to be solved meaning also to be cracked:
“Users now find the words easier to read – but so do machines.”
According to Wilkins and the tests he did, the new captchas – with no horizontal separator – are 10 time more easy to be solved!!!
Read the full article here!

A lot has been said and written about CAPTCHAS.

It has been said that Captchas suffer from lack of efficiency in preventing spam mail,
That Captchas are easy to be cracked by bots,
That human users get pissed off when they try to decipher Capchas,
That Captchas discriminate disabled users with sight problems or dyslectic persons,
That it’s about time to change the system…etc,’ etc’,

Well, incidentally, I’ve read an article lately about reverse Captcha and I said to myself:
Wow! That’s a great idea! Why haven’t all those smart guys thought about it earlier…

The idea of Reverse Captcha is based on a system which tries to trap the bot spammer, not the human user.

How?
Well, the well known Captcha sets a turning test for the human user before submission. Usually it consists an image with distorted alphanumeric letters and the user is asked to decipher and copy into a certain blank field. The system is based on an assumption that bots are not intelligent so they are doomed to fail. Unfortunately, robots become more and more “smart” thanks to high technology, and so a great percentage of Captchas are cracked.

Reverse Captcha is a turning test which bots can deal with and but humans will fail! How? Very simple: BY using a hidden filed which humans do not recognize. Bots fill out every field trying not to miss anything, and so they are trapped and filtered out of non desire submission.

A genius idea!

As a kid who was raised in a world of fantasies and fairy tails I believed the world is divided into two groups: good guys and bad guys. Naturally the good ones were my heroes. They were winners, never lost a battle and all the legends and fairy tails had a happy end.
As I grew older my perception has changed. I began to realize that the larger group belongs to “bad guys”.

What’s the connection between good and evil to Captcha?
Well, Captcha belongs to the “good guys”. It is based on the idea of assisting websites to filter automated bots and to enable registration to web sites for human being users. This small test of an image with distorted alphanumeric characters enables to tell apart humans and machines.

On the other hand stands a smart competitor, i.e, spammers, hackers, web sites that wish to promote ranking in S E O engines, who works hard by using bots to crack Captcha – not without success.

Abusing Captcha
Another variation of fighting Captcha is abusing it instead of cracking it.
The following information which came online a couple of monthes ago, under the headline “Paypal Fraud With Captcha” tells about a phishing URL of Paypal (Paypal allows  buyers on line to transfer money to merchant account without exposing his credit card while shopping), which asks for feedback on shopping on line, but before giving his feedback the user has to fill personal details: his name, e mail address and Paypal password. Afterwards, a Captcha test appears which users have to decipher and enter.

It’s so simple. Now the way to accumulate personal information and create faked accounts is free! No need for bots, no need for hard work, just exploiting good will of innocent users by the help of “good guys Captcha”…

By the way, the phishing URL has been blocked by “Trend micro Smart Protection Network”, so we have a happy end after all!

For those who have decided to protect their website and / or online services by using Captcha, these are just some of the sources where you can get your free Captcha plugin / script.
If you are not sure which of the following suits your needs or technical knowledge, check this list of considerations regarding Captcha implementation.
In any case, implementing Captcha should be easy.

10 Resources for Free Captcha

1. Free Captcha by reCAPTCHA – You must sign up to the site in order to use their free captchas.

2. An open-source free PHP CAPTCHA script by Securimage

3. Free Captcha images by captchas.net.

4. Free ASP security image generator software by Web Wiz Guide.

5. Free PHP Captcha scripts by thefreecountry.com.

6. Free Captcha by Protect Web Form.

7. A free Captcha generator by Captchator.

8. Free captcha script by Andyydev.com.

9. Captcher (=a PHP script that generates and verifies captchas) by White Hat Crew.

10. VidoopCAPTCHA – a free image Captcha by Vidoop (read more about it on our post: Image based Captcha).

For other security solutions that work like Captcha, feel free to read this comprehensive post by Netwaver:
34 Free Captcha Script and Anti Spam Services.

Got some free Captcha resource to recommend on?
Write it down on the comments section below…

Captcha, an acronym for “Completely Automated Public Turning Test to tell Computers and Humans Apart“ is a challenge-response test used by websites before user’s registration. This test is mostly based on distorted text with textured background and placed into a small box given at the bottom of the page registration.

The reason websites use Captchas is a strong wish to filter spam sent by spam bots.
Yet weak Captchas can be defeated by PWNTCHA!

What is a PWNTCHA?

Captcha, is a decoder project that decodes Captchas by using visual techniques. It stands for “Pretend We’re Not a Turning Computer but a Human Antagonist” as well as PWN Captchas.

Some Captchas are pretty weak. They consist of one single distorted word and an image, the letters are not rotated or not rotated enough, there is no deformation, or weak deformation, no color variation and weak perturbation. Such Captchas are cracked by PWNTCHA 92% of the time, in a pretty short time (somewhat around 10 seconds! Not more! )

Some harder Captchas, more challenge response tests, consist of 10 words displayed in clutter and distortion and the user is asked to name 3 of them. PWNTCHA succeeds to decode those Captchas 33% of the time.

As a matter of fact PWNTCHA proves the inefficiency of the common Captcha!

Maybe time has come for Captchas to be more difficult for humans as well as computers?…