Protect You Online Forms from Abuse

Problem

You have a script that is valuable to you and your customers. You want to keep other webmasters and programmers from creating a script which will access it automatically without your knowledge. This will keep your bandwidth down and also keep bots from using your valuable script.
You have an online form that has enormous value to your customers. It is free for them to use. But you are concerned other webmasters have created a bot or script which accesses it automatically, running up your bandwidth and costing you more money.
You require registration, and a malicious user could create a numerous sham accounts for malevolent purposes. So what can you do to keep hackers from counterfeiting requests?

Solution

We recommend you use a mechanism known as a reverse Turing test or CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart). Turing test uses pessimal print which is low-quality images of machine-printed text synthesized pseudo-randomly over certain ranges of words, digits, typefaces, and image degradations (see example pics). It has been proven that pessimal print is legible to human readers but illegible to the optical character recognition (OCR) systems. The slow pace of evolution of OCR and other species of machine vision over many decades suggests that pessimal print will defy an automated attack for many years.

For protection of your Perl/CGI and HTML forms from abuse by automatic systems and scripts we suggest you use the package shown here.

Description.
Allows you to protect online forms from abuse by carrying out on-the-fly Turing test (read more).
Does not require additional applications, including databases, sessions, folders with pictures and fonts etc.
Easily adaptable application allows you to change parameters of the picture such as the size, font, colors, degree of distortion, quantity of symbols, etc. quickly.

Demo.

Package includes.
The Perl Module we have developed.
All the necessary scripts.
Examples.
Documentation.

Requirements.
Installed Perl module Image::Magick.

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