Authentication picture

[stjulian]

I have seen on many websites the use of some sort of program to generate a
random character string distorted and warped with lines making the resulting
graphic ideally only human readable.

The theory is to prevent automated login programs.

I don't know what they call this type of component so I really don't know
how to google it.

Do you know any source for this type of thing?


Julian

 

[Kyle Peterson]

there is a name used for those things...of course I can not think of it at
the moment

basically the page with the form randomly generates some text, displays it
on the screen in one way or another, stores it in a session variable, asks
you to type in what you see, then the page the form posts compares what you
entered to what is stored in the session variable

all pretty easy except for the method of displaying the text it on the 1st
page... which can be as simple as images named after numbers and letters ...
or a component actaully generating an image of the text which is harder for
any bots to figure out

In my opinion for the most part just displaying the text as text is fine for
the average site... because someone would still need to take a lot of time
to write a bot to do posting at your site

bigger sites where its more likely someone would spend time setting up a bot
to post of course need the text diplayed all in one image and then it helps
to mess the text up a little..

some sites go a little extreme with messing up the text... and even a human
will interpret what is says incorrectly

 

[Bob Lehmann]

It's called CAPTCHA...
http://www.google.com/search?q=capt...ient=firefox-a&rls=org.mozilla:en-US:official

Bob Lehmann

 

[stjulian]

It's a great start!
Thank you so much

Julian

It's called CAPTCHA...
http://www.google.com/search?q=capt...ient=firefox-a&rls=org.mozilla:en-US:official

Bob Lehmann

 

[Frontier]

And if you're looking for an ASP component to do this...use Gflax.
It's free for non-commercial purposes, doesn't display ads - and it's
lightning fast using low CPU resources. Can be downloaded here:

http://perso.wanadoo.fr/pierre.g/xnview/engfl.html

With this compoent, you can draw in many different shapes, formats
etc. The only thing the component is missing (imho) is
anti-aliasing...(smooth edges on text).

Sincerely,
Klaus J.