Dynamic Access Codes

  • Thread starter Thread starter Jim
  • Start date Start date
J

Jim

Lately, I've been seeing a lot of those dynamically created access code images
on web forms. You know, some little jpg or gif image that has a random series of
letters and numbers. The form says something to the effect, "Enter the code you
see in the image. This is to protect you from webcrawlers...."

What are these images called? Is there some class in the framework that handles
these?

I did a lot of searching for things like "Dynamic access codes", but I can't
find a definitive name for them. I must be way off base in my searching. Can
anyone help?

Thanks!
 
Hi Jim,

I think there are other solutions available for this, rather than
implementing it yourself, I haven't seen any open-source implementations.

I would also be interested to know how they do it. It's seems easy to create
an image by drawing text, but how do they distort the text ???

www.captcha.com provides this explanation of the "Dynamic access codes" :

A CAPTCHATM is a program that can generate and grade tests that most humans
can pass, but current computer programs can't pass. For example, humans can
read distorted text as the one shown below, but current computer programs
can't.

In short, such a code is used to keep out Web-Bots.

Regards,

Cerebrus.
 
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