Ideas for a CAPTCHA-less CAPTCHA?

punky · 25-09-2009, 16:59

A quick definition: A CAPTCHA is a little test to make sure that forms submitted on the internet are filled out by a human, not a machine. Often says you ahve to type characters from a distorted picture.

I used to get a lot of spam in a few forms I ran until I coded my own CAPTCHA (before the reCAPTCHA days).

I'm trying to do a new script. I want a slick, unintrusive feel without the cumbersome CAPTCHA. Can anyone think of any unique ideas?

I do know NoBot from the AJAX toolkit but i'm trying to do this in Linux & PHP.

Cheers.

Kymmy · 25-09-2009, 17:09

I swapped my Captcha over to Recaptcha and had a 99.9% reduction in spammers getting through

A few sites use simple questions from a simple list.. (perhaps even relevant to the site)

When I was looking at recaptcha I though about possibly using a click on picture where you selected two or three items in a row on the same picture but soon realised that would get complicated as you'd need to map out various pictures..

Bots though use OCR to recognise the letters, perhaps something as simple as a recognition picture, for example show them a boat and expect 'boat' as the passphrase, or show them a ball and expect 'ball' as the passphrase..

**Damien** · 25-09-2009, 17:16

Microsoft Research have a project which shows pictures of, say, animals and asks the user to identify which one is the dog and so on. Computers are very bad at this while humans are not:

http://research.microsoft.com/en-us/...ojects/asirra/

---------- Post added at 16:16 ---------- Previous post was at 16:13 ----------

Otherwise I would go for reCaptcha. It's not that cumbersome imo.

punky · 25-09-2009, 17:24

I've done pictures before and simple questions. Its not much better than the existing CAPTCHAs.

i'm wondering if I can craft something like which is a CAPTCHA but doesn't make the user think they are doing one. Maybe something server-side or via JS.

NoBot is nice but I wondered if anyone can think of something out-of-the-box. Something that's not really been done before.

Kymmy · 25-09-2009, 17:57

Well if it's within a java window (or even flash) doubtful if the bots could read it...

Taf · 25-09-2009, 18:49

One site I vist show a word with a letter missing. You just have to put in the right letter.

I suspect only one specific letter is possible.

punky · 25-09-2009, 19:04

Quote:

Originally Posted by Kymmy

Well if it's within a java window (or even flash) doubtful if the bots could read it...

Flash is an idea...

Kymmy · 25-09-2009, 19:22

Is there perhaps a dynamic way to encode letters in a flash video??

punky · 25-09-2009, 19:32

Quote:

Originally Posted by Kymmy

Is there perhaps a dynamic way to encode letters in a flash video??

I meant just doing the form in flash.

I'm trying to avoid the user jumping through any hoops, not just different ones.

Kymmy · 25-09-2009, 19:52

Hmmm, never thought of that, would simplify things

Druchii · 25-09-2009, 19:55

Just do it with CSS?
Create a pattern resembling an image etc. Surely it's possible?

That way nobody has to use flash, and just about all browsers will be able to display it.

punky · 25-09-2009, 19:57

Quote:

Originally Posted by Druchii

Just do it with CSS?
Create a pattern resembling an image etc. Surely it's possible?

That way nobody has to use flash, and just about all browsers will be able to display it.

i'm trying to avoid getting the user entering in codes or anything like that. I've done loads of different CAPTCHA's before.

Aside from doing it in Flash, I don't think its really possible.

altis · 25-09-2009, 21:15

I've got some PHP that does a pretty good job of detecting spammers. There's lots of little tricks you can use to detect whether your form is being filled in by a script without the user having to read anything from the screen.

<touches side of nose>

When I'm back on my own machine I'll PM you the details.

punky · 25-09-2009, 21:22

Cheers for that mate, nice one