On 6/11/07, Daniel Brown <parasane@xxxxxxxxx> wrote:
On 6/11/07, Robert Cummings <robert@xxxxxxxxxxxxx> wrote: > On Mon, 2007-06-11 at 12:01 -0400, Robert Cummings wrote: > > On Mon, 2007-06-11 at 10:38 -0400, tedd wrote: > > > Gnag: > > > > > > I know we can beat this thing to death, as we have in previous > > > threads and I don't anyone wants to travel previously traveled ground. > > > > > > However, Rob said: > > > > > > "A good captcha will try to exploit a computer's weaknesses." > > > > > > So, let's expound on that -- what do you consider to be a computer's weakness? > > > > Well for instance as humans we can fairly easily recognize similar > > shapes. We can recognize an apple whether it is red, green, yellow, has > > a stem, has a leaf, is half eaten. A computer might recognize a circle, > > and might guess that the circle is an apple based on further analysis. > > But we as humans could recognize it as an apple even if we stretched it > > a bit so it was no longer circular, or as I said, if it was a crescent > > because someone had taken a huge bite out of it. This is something > > humans excel at... inferring information from similar previous > > experiences. > > > > Taking the image captcha to a different level, one could combine our > > ability to understand language as well as imagery. For instance we could > > have an icon repository of animals, vehicles, plants, etc (very obvious > > ones anyways). Then to create a captcha we could randomly select X > > icons, slightly morph them to spoof matching them within the captcha > > image itself, then ask: > > > > What animal do you see in the above picture? > > > > I think someone already said microsoft or someone does something > > similar. The principle is that we know what generally constitutes an > > animal and a computer does not. Similarly, an audio complement would be > > to have a background sound of maybe low level radio chatter overlaid > > with the sounds of various everyday items... then one could ask: > > > > What did you hear ringing? > > > > Possible answers... a bell, the telephone, an alarm, etc. > > > > The problem then becomes an issue of people who can't spell or are > > terrible at recognizing everyday things. > > I've just been inspired by my childhood... Sesame Street CAPTCHA... > > "Which of these things doesn't belong" > > :) > > Cheers, > Rob. > -- > .------------------------------------------------------------. > | InterJinn Application Framework - http://www.interjinn.com | > :------------------------------------------------------------: > | An application and templating framework for PHP. Boasting | > | a powerful, scalable system for accessing system services | > | such as forms, properties, sessions, and caches. InterJinn | > | also provides an extremely flexible architecture for | > | creating re-usable components quickly and easily. | > `------------------------------------------------------------' > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > Robert, I really like that idea. I'd suggest adding either radio buttons or a drop-down list of, say, four items.... but then there's a 25% chance that automated software could still get in, so in reality, it's only blocking 3/4 of the attempts at automation. Because otherwise, you'd have to have a cAsE-iNsEnSiTiVe regexp check (and possibly a database of common mis-spellings) to check against. -- Daniel P. Brown
If you make multiple choice items, a good app would probably just try max 4 times :P, so you need to check if the user did actually fail the first time... Tijnema
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