[access-uk] Time to Kill Off Captchas: Scientific American

From: Gordon Keen <gordonkeen@xxxxxxxxxxxxxx>
To: access-uk@xxxxxxxxxxxxx
Date: Wed, 29 Feb 2012 08:39:03 +0000
Thought the list might be interested in this article...

http://www.scientificamerican.com/article.cfm?id=time-to-kill-off-captchas

Time to Kill Off Captchas

Image: Illustration by Thomas Fuchs

Whenever there’s a problem in the modern world, we try to solve it by building 
barriers. Music piracy? Copy protection. Hacked Web sites? More complicated 
passwords.

Unfortunately, these barriers generally inconvenience the law-abiding citizen 
and do very little to impede the bad guys. Serious music pirates and Web 
hackers still find their way through.

Maybe all the hurdles are enough to thwart the casual bad guys. That seems to 
be the thinking behind the Web blockades known as Captchas. (It’s a contrived 
acronym for Completely Automated Public Turing Test to Tell Computers and 
Humans Apart.) Surely you’ve seen them: visually distorted words—sometimes real 
English ones and sometimes nonsense words—represented as a graphic when you try 
to sign up for something online. You’re supposed to type the words you see into 
a box.

Captchas were designed by their Carnegie Mellon University inventors to thwart 
bots (automated hacker programs) that might bring online services to their 
knees. For example, some bots sign up for Hotmail or Yahoo e-mail accounts by 
the thousands for the purpose of spewing spam. Some post bogus comments in 
hopes of raising a site’s search-results ranking.

In theory, only an actual human being can figure out what word is in the 
Captcha graphic. The letters are just twisted enough and the background is just 
cluttered enough that a person can read them, but not a computer. Good guys in, 
bad guys out—the perfect barrier.

In practice, Captchas have just replaced one public nuisance with another. 
First of all, the images are often so distorted that even a human can’t read 
them. That’s a particular problem in nonsense words like “rl10Ozirl.” Are those 
lowercase Ls or number ones? Zero or letter O? Second, there’s the vision 
thing. If you’re blind, you can’t do a visual Captcha puzzle.

The best Captchas (if that’s not an oxymoron) offer alternatives to fix these 
problems. There might be a button that offers you a second puzzle if the first 
is too hard to read or an audio Captcha option for blind people. Above all, 
though, increasing evidence shows that Captchas are losing the technology war. 
Researchers and spammers have both been able to get around them.

There have been efforts to replace visual Captchas with less user-hostile 
puzzles. Some ask you to take an easy math test, answer a simple question, 
identify a photograph or listen to garbled audio. All of them exclude one group 
or another, though—such as non-English speakers or deaf people.

Overall, the Carnegie Mellon team estimates that we spend a cumulative 150,000 
hours at the gates of these irritating obstructions every single day. In a 
newer variant, called reCaptcha, at least that time is put to public use. You 
see a muddied-looking word that comes from a wonky scanned Google book; when 
you type what it really says, you’re actually helping out with the process of 
cleaning up and recognizing an actual text.

Nevertheless, we the law abiders are still wasting 17 person-years every single 
day. That’s a disgraceful waste of our lives. Surely there are better solutions 
worth exploring.

Maybe we should invent a voluntary Internet identity card so we’re already 
known when we sign up for something. Maybe Web sites should enforce a 
short-term limit of one new account or posted comment per “person.” Or the Web 
site should look at the speed or irregularity of our typing to determine if 
we’re human.

Or fingerprints. Or retinal scans. Something.

Spammer bots are a problem, yes. But Captchas are a problem, too. They’re a 
bother, they’re not foolproof and they assume that everyone is guilty until 
proven innocent. What Captcha really stands for, in other words, is Computers 
Annoying People with Time-Wasting Challenges That Howl for Alternatives.
[access-uk] Time to Kill Off Captchas: Scientific American

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