Ads Captcha

As you may already know by now, Captcha is a common approach to prevent access of users that aren’t human to all kinds of websites. The captcha is a kind of test that requires verification of distorted image plus textual content which is deciphered easily by humans but not by computer bots. 
However, it appears that this simple system may also prevent access from a certain group of human being: disabled people such as blind, low-vision, or people who suffer from cognitive problems (dyslexia). Once a low vision user cannot decipher the image displayed on the Captcha, he cannot access the specific website that uses the captcha protection and thus can not open an account, comment on a forum or blog and so on.

To make a long story short - Captcha can tell human and bots apart but cannot recognize human with disabilities who are not bots and fail the test because of their disabilities…

Captcha Alternatives
But do not worry. There other alternatives for Captcha:

One of the alternative methods is a sound test also known as “audio captcha“. It requires the potential user to listen to some sounds which are played on a noisy background, filter the sounds and repeat them. It is a good solution for low vision or blind users, but not for deaf people or users who don’t have a good hearing.

 Other captcha alternatives are as follows:
Spam filtering – software for blogs contain spam filters targeted to delete spam messages. More advanced systems are able to control spam attacks and filter permanently or temporarily spam contents using the IP address of the user.

Heuristic checks – are based upon the user’s data such as requests, pages he has visited, IP address, data entry or signature data and assist in detecting robot users. 

Single sign-on – This system is similar to a passport. It utilizes visual verification. No doubt – it’s highly recommended for people with disabilities.  

Public key infrastructure solutions – This is another alternative solution not used yet but may help low vision users – to use certifications issued by government or other trusted authorities that verify their identities. The disabled user will have to telegraph the site, inform his or her disability and get access to the site’s service.

Biometrics – Another tool, to be used together with the single sign–on system (using D.N.A / fingerprints). Microsoft has already developed a new system of Biometric verification but it will take years until the biometric hardware will penetrate into the market.

 To sum up, Captcha is a good solution, but not for all. When it comes to disabled people with low vision or hearing and other disabilities, one must consider some other security tools and / or software, such as the captcha-alternatives mentioned on this post (spam filters, heuristic checks and so on).

Like the following captcha comics?

Check this excellent site…
(And please let us know if you run into additional funny stuff)

Not too long ago the Gmail registration, which supposed to be secured by the highly popular captcha test, was cracked by spammers. What are the implications of this event? 

First, let’s start with clarifying the meaning of that strange word “CAPTCHA”.
Captcha is an abbreviation of “Completely Automated Public Turning test to tell Computers and Humans Apart”.

The captcha test is used all over the online world by all kinds of websites who want to verify the user who’s signing up to them is a human and not a robot or some automated machine.
In other words, by using the Captcha test all spammers are supposed to be filtered out.

Unfortunately, it has been discovered lately that spammers have succeeded to create bots that are capable to open Gmail accounts and thus can attack and abuse the infrastructure of Google mail.

Gmail, as you may know, is a free service by Google. It is considered as a highly user-friendly, simple and flexible platform that enables over 6000 MB of storage for free (plus more 10GB for a symbolic fee of 20$ a year) and it has tens of millions of satisfied users from all over the world.

The bots succeed to open accounts by feeding all the data required on the sign up page and then cracking the Captcha (usually displayed at the bottom, at the end of the registration process). Bots are trying to create new accounts as many as possible, by using 2 hosts in the process of cracking the Captcha code. Once the first host fails to break the code the second host gets into action.
The cracked Captcha codes are stored in a domain located at United States.

Luckily, Captcha is not an easy test for machine computers or bots and in spite of endless repeated cracking attempts only 20% Captchas are busted. 

Is it possible to overcome the Captcha cracking problem on Gmail registration process?
I guess only time will tell…

Who needs Captcha protection service?

As a matter of fact – everyone needs captcha!
Whether you are a private navigator with a private e-mail  or an owner of a blog or a forum – if you don’t want others to abuse your platform and / or spam it for their own good, you need protection.

Why do people use spam?

One of the reason for online spamming is the wish to achieve a higher “Search Engine Ranking”, which can be done, among other tactics, like SEO and advertising networks, by getting relevant links to your site.
How can one get more links to his website? Among other, getting additional links can be done by simply inserting messages with your link into other websites that allow it, like forums or blogs.

Why do business marketing use spam?
For the same reason – to achieve a higher ranking as well as better traffic to their business through posting advertisements to mailboxes of innocent users as well as to all kinds of online platform (blogs, forums and social media platforms such as facebook, digg and even flickr).

How is it done?
It should be noted that only a minority of online business uses manual spammers while the majority uses spam robots.
The automatic spamming is done by bots that spider the web for all kinds of  users forms and then post a spam message of advertisement.

Can you protect your e-mail box or website from spammers?
Yes, you can. One of the options is to use Captcha and thus prevent registration of spamming bots to your site, or, if we talk about mail-spamming, to use Hydmail which is a special kind of Captcha programmed for mailbox and cannot be deciphered by spam robots.

Click here to read more about captcha security applications

An advertising network (also known as “ad network” or “banner network”) is a group of websites connected by a sort of agency that allows them to use its online platform for ads exchange.
In other words – advertising network contains two groups: advertisers and publishers (while it should be noted that one can be a publisher and an advertiser at the same).

The forms of advertisements that could be exchanged through an “advertising network” are varied and include, among other, banners (or image ads), textual ads, landing pages and video advertisements.

The main types of online advertising networks are blind networks, targeted networks and representative networks.
Being a part of a Blind Network enables you to advertise your service or product for a low price, but with no control over location (you can’t choose where your ads will appear).
In a Targeted Network the advertiser’s ads appear in a highly relevant websites (this is why it is called a targeted network) from the same niche and context.
A Representative Network offers a revenue share model (payment = a certain percentage of sales revenues generated by clients who were referred via the advertiser’s ads). Contrary to the “blind network”, the representative network is completely transparent in regards to letting the advertiser know where his advertisements will run.

Other terms relevant to the field of online advertising network are first-tier and second-tier networks.
A first tier advertising network is a big network of advertisers and publishers (all are part of the network) with high quality traffic, which is usually used by second-tier networks.
The “big 3” (Yahoo! Google and MSN / Bing search engines) is an excellent example of first-tier networks

A second-tier advertising network is, comparing to the first-tier network,  a smaller network in which the main source of income comes from syndicating ads from other advertising networks.

What is ReCaptcha?

To understand what is reCaptcha we first need to define the term “Captcha”.
Captcha is a test made of an image and distorted text that has to be solved by human users when they want to subscribe to websites that want to make sure the user is a human being and not a bot or a computer (= preventing spam).

Recaptcha is a system that uses Captchas to digitize books text for the same purpose: to ensure the user is not a computer or bot.
Computers can’t navigate sites that are protected by Captchas.

Every day 200 millions of Captchas are being solved. It takes about 10 second to decipher a Captcha but about 150,000 hours of work to accumulate them. This is where reCaptcha comes and help in channeling the big effort spent on Captchas solving into reading books by digitizing process.

How is it done?
By using Optical Character Recognition (OCR) program books text and pages are scanned and transformed into forms that are impossible for computers to decipher. Every word that can’t be read by OCR is placed on an image and displayed together with another word which can be read correctly, that is a “control word”. The user who wants to subscribe to a site that demands verification of human users, is asked to decipher both words. If he solves the “control word” the system assumes the answer is correct for the new one also.

Captchas are taken from internet archives, the New York Times and alike and can be used as protector from mail spam bots as well.