One of the most useful – and maddening – tools in the fight against spammers is CAPTCHA technology, better known as pictures of distorted words and letters that accompany most online form and require the user to identify the letters or be branded a spam program or bot.
The strange acronym stands for completely automated public Turing test (CAPTCHA) to tell computers and humans apart. A Turing test refers to mathematician and cryptographer Alan Turing's attempt to define sentience in terms of a test. Specifically, if a computer could fool a human into thinking that it was human, that computer would essentially be sentient.
But as useful as standard CAPTCHA tests are, they present two basic problems:
• Some are too distorted to be deciphered.
• Spammers are already starting to beat them.
XMoney General Manager Q Boyer told XBIZ that he's been confounded by the occasional CAPTCHA.
"I've entered the wrong character from those dynamic gifs that contact forms use to prevent posting by bots," he said. "The font was chosen poorly and was hard to read, so i was entering 'g' instead of 'q,' that kind of thing. To me, though, that's a failure on the captcha test creator's part, and not the user."
Playboy webmaster Brett Gilliat told XBIZ that although he's been able to decipher every CAPTCHA he's encountered, he's heard about plenty of work being done to thwart them. He pointed to the free, downloadable MySpace FriendBot, which trumpets its CAPTCHA-beating abilities at the top of its homepage.
In February, spammers bypassed defenses at no less than Microsoft to open huge numbers of phony Live Mail accounts. Gmail's CAPTCHA has been cracked, too, and while in both of these high-profile cases the spammers' success rates were less than half, the incidents still raise concerns.
So if traditional CAPTCHA is in danger of becoming obsolete, what's the next step? Better pictures and better questions.
Visual CAPTCHAs ask the user to look at pictures and identify specific elements of them. For example, a user might encounter a picture of a moon shining over a lake and be asked to click on the moon's reflection to prove they're human. Web guru Brandon "Fight The Patent" told XBIZ that other CAPTCHA might use the same ideas and ask users to match up images to prove they're human.
An even more high-tech solution might be a 3D CAPTCHA. These CAPTCHAs would give webmasters a simple collection of poseable, 3D images that could be moved into countless positions. Users would prove their humanity by identifying specific body parts on a certain figure.
For example, a 3D CAPTCHA might show a man standing and a man sitting in a chair. The user would then have to click on the head of the man sitting in the chair.
This form of CAPTCHA an advantage over image-based tests because it would give webmasters a huge selection of positions and bodyparts from which to construct tests, as opposed to having to host a huge collection of different images with their own unique tests.
But regardless of the future of CAPTCHA, Boyer said he's looking forward to it – even if he fails the occasional Turing test.
"Sometimes I wonder [if I'm a robot]," he joked. "It's like being a character in a Phillip K. Dick novel."
