It’s quite time consuming to create a new system as captchas are somehow easily defeated and not user friendly especially to vision impaired/challenged visitors (i.e. blind or color blind). So because of this, I’d like to stay away from images and color questions although I have many great ideas involving images and funky color tests. Text is probably better for everyone and was wondering what kind of “text-based challenge” would work best?

So I thought about it for about 5 minutes and came up with a few example:

A) Math – What is X + Y? Very easy to implement but easy to break as well. Unless you combine with option 2 below. Also, if you go too far (what is the square root of 2?) then you’ll lose some visitors. I’ve seen this one personally and I’d be curious to know if it really works or not.

B) Logical multiple choice – Like “Passe partout” (if you’re from Quebec you know them). You have to click on the only sentence which makes sense. For example:

1. There’s a cabbage in my ear
2. There’s a cabbage in a microwave
3. There’s a cabbage in the toilet

Only #2 really makes sense. Option #3 DOES makes sense but #2 overweights #3. I think this is quite hard for a bot to defeat. However, building enough sentences takes some time. Building a good algorithm help but you will need to come up with groups of words, verbs and so on. if you don’t have a big enough database of sentences, it will be defeated. Then again, there are many ways to write cabbage, I could get inspiration from my spam folder! I haven’t seen this technique on any site so far.

C) Complete the missing word – Like above but you have to find the missing word. This solution was also mentioned on the ISC web site. For example:

The ____ is stuck in a tree.

1. kite
2. dog
3. carrot
4. ham

The obvious answer is #1 although all possible choices are somehow possible. Same problem with the above solution: you need a lot of sentences to keep up with spammers. I also haven’t seen this technique on any site so far.

That’s about all I could think for tonight as my brain is already asleep. So if you have any solutions, please let me know as I’d like to hear from you. Let this be the challenge of the week!