Re: CAPTCHA image validation in web form

[Nathan Andelin <nandelin@xxxxxxxxx>]

> From: Pete Helgren
> Couldn't you generate random placement and valid responses each
> time and store them on the server?  So, boat may be in the first position
> the first time and then in the 4th position the second time, etc.

Well, the example that Guillermo posted had just 1 image displayed.  And the challenge was to select the appropriate description from 7 radio group options; only one of which would be correct.

But I think you hit upon a key to a strong captcha.  The number of options should be large.  And the challenge for the client should be random.

It's a lot of work to catalog a large number of images of familiar people, places, and things; along with appropriate descriptions.

But the random idea seems like a good lead.  I've been looking at the CEERAN0 api, and calling it from RPG to come up with a procedure for generating random numbers within a parameter range - like give me a random number between 5 and 8, for example.  Or, give me a number between 1 and 100.  I think I'll add something like that to my toolkit because it seems like something that could be useful for captcha and other things.

Nathan.