Will the real user please stand up?

The vision of the World Wide Web was to build a global community of computer users who exchange information. In its infancy, the type of information being passed was data for analyst by the scientific community, and evolving near the end of the century as a means of connecting people. You might remember how cool it was to receive your first email from a colleague, or seeing family pictures from last year’s Christmas get-together.

The web has been heading toward a user-fed library of information, with sites like YouTube, Facebook, and Wikipedia. This has become known as Web 2.0, and with its influence people are spending more time on the internet sharing vast amounts of resources, and increasing productivity. Not just individuals, but companies are contributing and using the web as the main contact point. When someone asks you to check out their company, the first thing that most likely comes to mind is, what is your website? In fact, it’s probably the dot-come of the company name. Or how about when a potential candidate is applying for a job. Fewer places are accepting faxed resumes and turning to web forms for applicants to contact the employer directly. What a wonderful system of efficiency and organized data collection.

The system was so effective in communicating to users that certain groups saw it as a potential delivery method for the own message. And many times these messages are inappropriate or not beneficial, and hence excess irrelevant information – later termed as spam. Though my need for cheap prescription drugs may vary from the next guy, I probably don’t need to be told that by 20 or 200 emails daily. Spam has not only increased in freqeuncy and quantity, but has expanded from simple email messages to filling out contact forms. In the past, end users would fill out web forms to inquire additional information or request for a service. With spambots, site owners are now receiving these junk messages in their request forms. Now imagine automating that to receive several fake requests daily on every form used on your site. You can see why it weighs down productivity because you now have to ‘filter’ out the junk from the real messages.

Enter CAPTCHA, a method to separate the automated bots from real users on your website. The term “CAPTCHA” was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas J. Hopper (all of Carnegie Mellon University), and John Langford (then of IBM). It is a contrived acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart”. The tool would require the user to recognize the letters from the image and input them into a verification textbox. The majority implementation of CAPTCHA used of the web is an image with letters in it, sometimes with a graphic background or distorted. These transformations applied to text make it almost impossible for non-users to submit form content*. The CAPTCHA system uses a library of images or creates them just in time when the form is generated. The user gets a new CAPTCHA when they use the form. This separates a human user from an automated program. To comply with accessibility guidelines, audio CAPTCHAs have been introduced. Similar to a text CAPTCHA, it plays an audio file that reads out the letters for the user to input. The goal of CAPTCHA is to require a visual validation by an external user before information can be submitted. This reduces junk submissions from automated programs.

Say goodbye to junk messages through your web forms. Because spam bots were made to autofill a form that match predefined fields, CAPTCHA enables a method to prevent them from succeeding. CAPTCHAs are dynamically generated so they change with each new instance of an input form. If two bots were to visit the site, one bot might have a chance in matching the CAPTCHA (highly improbable) but on it’s next visit if it tries to put the same info, it would fail. I’m sure spammers are currently looking for other methods to circumvent CAPTCHA, but until then, forms are safe for web users and end users everywhere. Rest easy webers.

* There have been recent development in developing character recognition to break CAPTCHA forms. Hence we recommend a balanced implementation of images and transformation to make it harder for OCR.

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