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Web form protection against spambots

The internet is plagued by spambots, which are automatic scripts that fill out web forms and send spam to forums, blogs, guest books and other web forms. Most website administrators use two approaches in tackling this problem: the CAPTCHA method, and server-side or client-side obfuscation or active countermeasures. Both approaches have their pros and cons, so let us compare more closely CAPTCHA and software utilizing JavaScript for web form obfuscation.

Web form visual appearance

Although the code changes significantly, Web Form Anti-Spam makes protected forms appear exactly as if they were without protection. Website visitors will therefore never notice the difference.

CAPTCHA requires not only the input of an additional verification code, but also requires visitors to recognize blurred, colored and distorted digits and letters (as shown below). Such web forms look markedly different, while unprotected and colored graphics may conflict with a website design and color scheme, breaking up the web designer’s work.

Potential problems

CAPTCHA may be a problem when using an Internet browser with disabled images (ie when saving bandwidth and/or traffic). In such cases, the CAPTCHA code image will not be displayed, which inconveniences the user and requires the browser image function to be constantly enabled.

A form protected with Web Form Anti-Spam cannot be viewed if JavaScript is disabled in the browser (instead it prompts a warning that JavaScript must be enabled). This is not a huge problem, as all modern Internet browsers support JavaScript. Furthermore, the number of people with JavaScript disabled in their browsers for security reasons is low and is decreasing with the growing trend of the Web 2.0 paradigm (which intensively uses JavaScript browser features).

Web form accessibility

Because Web Form Anti-Spam creates web forms with their original look, they can be read by screen reader software and narrated. Although the majority of CAPTCHA web forms can also be read using screen reader software, the actual CAPTCHA code image cannot be read. This means that the web form is rendered useless for visually impaired people.

Web form protected with Web Form Anti-Spam Web form with CAPTCHA ^Web Form Anti-Spam protected form >CAPTCHA protected form

Trial Version Download: 2.83 MB, 1.00.0.40, 19 May 2009.
(for Windows 2000, Windows XP and Windows Vista)

Web Form Anti-Spam is available for Windows 2000/2003, Windows XP and Windows Vista. The demo version is free to download and is free to use for evaluation purposes for 15 days.

7 November 2007
Xander Zerge
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