Re: CAPTCHA image validation in web form

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.