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Blender 2.49 Scripting by Michel J. Anders

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Generating CAPTCHA challenges

In many situations such as blogs, forums, and online polls (to name a few) website operators want to guard against automated postings by spambots without wanting to burden human visitors with registration and authentication. In such situations it has become common to provide the visitor with a so-called CAPTCHA challenge (http://en.wikipedia.org/wiki/Captcha). A CAPTCHA challenge (or just Captcha) in its simplest form is a picture that should be hard to recognize for a computer, yet simple to decipher by a human as it is, typically a distorted or blurred word or number.

Of course, no method is foolproof and certainly Captchas are neither without their flaws nor immune to the ever-growing computing power available, ...

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