Protecting online application form abuse

Hi,

 i have cold fusion web page (.cfm) where potential customers fills out credit application information and submit to us.At this point, anyone can poke around and can stumble upon this .cfm page and fill out the information and submit to us.

 However, due to no protection or verification process in place, we are getting one too many prank/fake applications and I like to do something about it.

 I  have seen examples of protection like requiring the result of multiplication of two numbers:   2 x 3 = 6 or the picture where I am supposed to select blocks in the picture where cars are seen ... etc.

What is the simplest and easiest way of protecting this page from abuse?

Thanks.