There are so many things that need to be done with this blogging platform. Several functions are still in the state the bake script left them. And I want to add more stuff.

  • Drafts
  • Stuff on the right-hand column
  • Search function
  • Enhanced user profiles
  • Etc.
But first and foremost I need to allow users to register themselves so they can add comments.

And for that I have decided I need a CAPTCHA.

I could use PHP's GD library to create your standard distorted-text-on-busy-background CAPTCHA, but I want to try something else.

I am thinking of a row of simple images--squares, triangles and circles. I will generate the images with GD so the file names are the same. Let's say there will be 20 images in the row.

I will generate some instructions tell the user which six images to use. The candidate user will then have to type in the color and shape of those six images. I will only have four colors and three shapes, so the users will abbreviate. For instance, a red square would be 'rs'.

That allows for 4^6*3^6 = 2985984 combinations, which would be good enough for my site. And with a little help from IP logging, it would probably be good enough for any site.

Here's a mockup:

colors: shapes
red = r
blue = b
green = g
yellow = y
 circle = c
square = s
triangle = t

Please enter the first letter of the color followed by the first letter of the shape for pictures: 8, 3, 9, 10, 17, and 12 captcha example Enter them in the order specified.

Update: I had my brother test this out. It sucks. I'll come up with something simpler.