User validation

[Timotius Pamungkas]

In some websites (let's take yahoo mail for example), when we want to register as new user, the site (yahoo) give us a distorted image, and we must enter string in that distorted image to validate us.

Actually, what is it for?I suggest that's for security (maybe to avoid something like "auto-register-bot"?). Am I correct?

What is the logic behind such a security prevention? How can we implement it using JSF?

Thanks

[Tim Holloway]

You are correct. Image-based verification is designed to keep bots out by requiring human intelligence.

Generation of one of these images isn't strictly a JSF issue - all you really need is an image generator and a place to keep the value that you'll check the returned data against. Whether there are any JSF-specific implementations of this function, I don't know.

[Fernando Lopez Jr.]

they are called captchas... :-)

[Abiodun Adisa]

Originally posted by Timotius Pamungkas:
In some websites (let's take yahoo mail for example), when we want to register as new user, the site (yahoo) give us a distorted image, and we must enter string in that distorted image to validate us.

Actually, what is it for?I suggest that's for security (maybe to avoid something like "auto-register-bot"?). Am I correct?

What is the logic behind such a security prevention? How can we implement it using JSF?

Thanks

You can implement it using Jboss Richfaces