How to avoid CAPTCHA ?

PHP programming forum. Ask questions or help people concerning PHP code. Don't understand a function? Need help implementing a class? Don't understand a class? Here is where to ask. Remember to do your homework!

Moderator: General Moderators

User avatar
Mds
Forum Contributor
Posts: 110
Joined: Tue Apr 22, 2008 8:56 pm
Contact:

How to avoid CAPTCHA ?

Post by Mds »

Hi.
Is it possible to avoid CAPTCHA in our websites?
Thank you
User avatar
califdon
Jack of Zircons
Posts: 4484
Joined: Thu Nov 09, 2006 8:30 pm
Location: California, USA

Re: How to avoid CAPTCHA ?

Post by califdon »

Mds wrote:Hi.
Is it possible to avoid CAPTCHA in our websites?
Thank you
Would you explain what you mean? What is it that you want to avoid?
User avatar
Mds
Forum Contributor
Posts: 110
Joined: Tue Apr 22, 2008 8:56 pm
Contact:

Re: How to avoid CAPTCHA ?

Post by Mds »

Thank you.
Well, almost always we should use CAPTCHA images in our form to avoid robots registering.
Like this : http://recaptcha.net/

I wanna to know, is it possible to avoid it.
Means , is there a way to avoid using CAPTCHAs and prevent robots registering.
Do you understand what I mean ? Image
User avatar
Stryks
Forum Regular
Posts: 746
Joined: Wed Jan 14, 2004 5:06 pm

Re: How to avoid CAPTCHA ?

Post by Stryks »

Sorry ... are you asking how to get around a captcha on someone else's site, or are you asking for alternatives to using a captcha on your site to prevent robot registrations?
User avatar
Mds
Forum Contributor
Posts: 110
Joined: Tue Apr 22, 2008 8:56 pm
Contact:

Re: How to avoid CAPTCHA ?

Post by Mds »

Sorry ... are you asking how to get around a captcha on someone else's site
Image Nope.
It was a simple question.
I wanna create a Form without any CAPTCHA images, and I wanna prevent robot registrations with a way except CAPTCHA Image
User avatar
The_Anomaly
Forum Contributor
Posts: 196
Joined: Fri Aug 08, 2008 4:56 pm
Location: Tirana, Albania

Re: How to avoid CAPTCHA ?

Post by The_Anomaly »

Mds wrote:
Sorry ... are you asking how to get around a captcha on someone else's site
Image Nope.
It was a simple question.
I wanna create a Form without any CAPTCHA images, and I wanna prevent robot registrations with a way except CAPTCHA Image
You want to know if there are alternatives to CAPTCHAs for beating robots.

The only other thing I know of/seen are basically the same concept. For example, there will be a textbox with some random arithmetic, "2x2=" and the users answers it. I can imagine how this could be circumvented, but it is pretty cool.

The other thing I've seen are audio CAPTCHAs...but I doubt you'd want that. It's the same thing as a normal CAPTCHA, but the user is listening to the phrase instead of copying it from an image.
mikelbring
Forum Commoner
Posts: 38
Joined: Sat Jan 05, 2008 5:28 pm

Re: How to avoid CAPTCHA ?

Post by mikelbring »

What you do is create a text field called url and then hide it with css. Not a hidden field but one hidden with css. If that field has any info in it you simply exit(). The only problem is people without css browsers will 'could' be hurt. I do this on my site and it seems to work like a champ. Might add captcha later on tho.
User avatar
The_Anomaly
Forum Contributor
Posts: 196
Joined: Fri Aug 08, 2008 4:56 pm
Location: Tirana, Albania

Re: How to avoid CAPTCHA ?

Post by The_Anomaly »

mikelbring wrote:What you do is create a text field called url and then hide it with css. Not a hidden field but one hidden with css. If that field has any info in it you simply exit(). The only problem is people without css browsers will 'could' be hurt. I do this on my site and it seems to work like a champ. Might add captcha later on tho.
Maybe I'm just an idiot, but how would that prevent bots from registering? They're generally programmed to fill fields called URL or something?
User avatar
Stryks
Forum Regular
Posts: 746
Joined: Wed Jan 14, 2004 5:06 pm

Re: How to avoid CAPTCHA ?

Post by Stryks »

Actually ... I could kind of see that working. The bot is probably going to have a list of ready-made answers for known field names. And even if it doesn't, it'll probably take a shot at all the elements of a form to try and pass validation.

So you hide the field, and if you get a form submitted with the value filled in, you know it's suspect. You could probably tie this method into a profiler, trying to find common elements between all suspect submissions. Even IP info could be useful over a big enough sample (though I wouldn't block anything on IP alone).

Not saying that it'd work ... but it seems an interesting possibility.
taylor28
Forum Commoner
Posts: 31
Joined: Tue Sep 16, 2008 11:55 pm

Re: How to avoid CAPTCHA ?

Post by taylor28 »

CAPTCHA would be nice to avoid bots I'd rather avoid bots than CAPTCHA. :D
User avatar
onion2k
Jedi Mod
Posts: 5263
Joined: Tue Dec 21, 2004 5:03 pm
Location: usrlab.com

Re: How to avoid CAPTCHA ?

Post by onion2k »

Field name randomisation helps too... the first time the form is loaded your "email" field might be called "website", next time it loads it's called "name", and so on. Randomising the field order helps too, so email is the first item one time the form loads, and second another time, etc, but that can have accessibility issues. Coupled with some strict validation it'll defeat most bots though.
User avatar
califdon
Jack of Zircons
Posts: 4484
Joined: Thu Nov 09, 2006 8:30 pm
Location: California, USA

Re: How to avoid CAPTCHA ?

Post by califdon »

What is the problem we are trying to solve here?
User avatar
onion2k
Jedi Mod
Posts: 5263
Joined: Tue Dec 21, 2004 5:03 pm
Location: usrlab.com

Re: How to avoid CAPTCHA ?

Post by onion2k »

califdon wrote:What is the problem we are trying to solve here?
Automated scripts (bots) filling in forms.
User avatar
califdon
Jack of Zircons
Posts: 4484
Joined: Thu Nov 09, 2006 8:30 pm
Location: California, USA

Re: How to avoid CAPTCHA ?

Post by califdon »

onion2k wrote:
califdon wrote:What is the problem we are trying to solve here?
Automated scripts (bots) filling in forms.
Yes, I think so, too. It's not avoiding the use of CAPTCHA. That's the point I wanted to make.

So why does the OP not want to use CAPTCHA? It's a pretty well established and widely used method. If we're going to discuss alternatives, we ought to be evaluating why CAPTCHA isn't adequate. Is it user reaction? Does it have any history of being defeated by bots?
User avatar
onion2k
Jedi Mod
Posts: 5263
Joined: Tue Dec 21, 2004 5:03 pm
Location: usrlab.com

Re: How to avoid CAPTCHA ?

Post by onion2k »

califdon wrote:
onion2k wrote:
califdon wrote:What is the problem we are trying to solve here?
Automated scripts (bots) filling in forms.
Yes, I think so, too. It's not avoiding the use of CAPTCHA. That's the point I wanted to make.

So why does the OP not want to use CAPTCHA? It's a pretty well established and widely used method. If we're going to discuss alternatives, we ought to be evaluating why CAPTCHA isn't adequate. Is it user reaction? Does it have any history of being defeated by bots?
CAPTCHA is not an adequate method. They're relatively easy to break, progressively more difficult for a user to enter as they get stronger, and they're usually very inaccessible for disabled users. Using a hidden form field, or randomised fields, makes life much harder for a bot and has no effect on the user at all. Much better than a CAPTCHA.
Post Reply