I'm working on a service request form, between 5 and 10 fields (depending on the service). *And, possibly, a recaptcha that the Security team is asking us to add.

The case is a user requesting an on-demand service which is additional to a purchase (sometimes free of charge, sometimes involving a fee).

There's no validation of the purchase code or username with any DB. User will have to fill in names, contact phone and e-mail (with format validation only).

I've tried to push for options like "solve the spam without involving the user", or.. math operations, e-mail verification (link sent to user, which is also asking effort from the user's side), slider (question to answer with a switch), multiple choice questions... BUT Security isn't confident about these custom security checks.

What will you say about the security of a custom option like this: Show a random image of an object (related to the seller business) and offer 3 possible options (radio buttons) for the user to answer the correct one**. E.g: a)Pencil b)glasses c)dog

Maybe too childish, but easier to complete than a reCaptcha, for sure.

I need to keep it serious, but easy for the user. A gamified option could be too much for this form.

Or, any ideas on a service similar to NUcaptcha that is secure, already functioning, which I can only insert in my form without building it? Perhaps based on math operations or random easy questions instead of distorted book lettering?

thanks for your comments!

2 Answers 2


In this case, you're looking for alternatives to Captcha first and foremost.

Perhaps have a look into this solution, where some coding smarts are used to determine whether or not someone is a bot. I believe it's called a "honey pot".

You'll also find some good solutions in this article, and here's another one.

Basically, you're trying to trick the bot into doing things a human would not do, rather than making it emulate a human.


In the case of showing an image and giving the user a choice to correctly name it; a bot will have a (in the example case 30%) chance at a guess.

You want the user to have to enter the answer by hand, and not select it, for that reason.

  • That's true. Thanks Evan! The math operations is what I will need. Something like the recaptcha but instead of blurry characters, an operation and a field to type answer. Hard to find...
    – redux
    Commented Nov 11, 2014 at 19:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.