Tracking you

Fingerprint scanners that work from 25 feet away.

Cell phones that can identify you by how you walk.

Radars that pick up your heartbeat from behind concrete walls.

Algorithms that can tell identical twins apart.

Eyebrows and earlobes that give you away.

A new generation of technologies is emerging that can identify you by your physiology.

And unlike the old crop of biometric systems, you don't need to be right up close to the 
scanner in order to be identified.

If they work as advertised, they may be able to identify you without you 
ever knowing you've been spotted.

Biometrics had a boom after 9/11.

Gobs of government money poured into face and iris recognition systems.

The Pentagon alone spent nearly $3 billion in five years, and the Defense Department 
was only one of many federal agencies funneling cash in the technologies.

Civil libertarians feared the worst as face-spotters were turned on crowds of citizens 
in the hopes of  catching a single crook.

But while the technologies proved helpful in verifying identities at entry 
points from Iraq to international airports, the hype -- or panic -- 
surrounding biometrics never quite panned out.

Even after all that investment, scanners still aren't particularly 
good at finding a particular face in the crowd.

For example; variable lighting conditions and angles, not to mention hats, 
continue to confound the systems.

Eventually, the biometrics market -- and the government enthusiasm for it -- cooled off.

The technological development has not.

Corporate and academic labs are continuing to find new ways to ID people with more 
accuracy, and from further away.

My, what noticeable ears you have. 

So noticeable in fact that researchers are exploring ways to detect the ears' 
features like they were fingerprints. 

In 2010, a group of British researchers used a process called "image ray transform" 
to shoot light rays at human ears, and then repeat an algorithm to draw an image 
of the tubular-shaped parts of the organ.

The curved edges around the rim of the ear is a characteristic -- and most obvious -- 
example.

Then, the researchers converted the images into a series of numbers marking the 
image as your own.

Finally, it's just a matter of a machine scanning your ears again, and matching 
it up to what's already stored in the system, which the researchers were able 
to do accurately 99.6 percent of the time.

In March of 2012, a pair of New Delhi scientists also tried scanning ears using 
Gabor filters -- a kind of digital image processor similar to human vision -- 
but were accurate to a mere 92 to 96.9 percent, according to a recent survey 
(pdf) of ear biometric research.

It may even be possible to develop ear-scanning in a way that makes 
it more reliable than fingerprints.

The reason is because your fingerprints can callous over when doing a lot of hard work.

But ears, by and large, don't change much over the course of a lifespan.

There's a debate around this, however, and fingerprinting has a much longer 
and established history behind it.

A big question is whether ear-scanning will work given different amounts of light, 
or when covered (even partially) by hair or jewelry.

But if ear-scanners get to the point of being practical, then they could 
possibly work alongside fingerprinting instead of replacing them.

Maybe in the future we'll see more extreme ear modification come 
along as a counter-measure.

Noah Shachtman and Robert Beckhusen.