This is a scientific American 60 second science.

I'm Christopher in D'Alga.

Got a minute?

Connecting your computer to the internet gives would-be spies an obvious entry point to your

machine, but other ways exist to Snoop, because even computers

that aren't connected to the internet broadcasts their activity in the form of electromagnetic

radiation. Basically your computer is full of transistors and they are switching a current from high to low depending

of is it a zero or a one of the bit that they're trying to execute.

A link is H, an electrical engineer at Georgia Tech.

When you do that, you're creating a voltage fluctuation and current fluctuation

and that basically creates electromagnetic field.

By hooking an antenna and receiver up to a laptop,

Saich and her colleagues were able to log the keystrokes of a computer in the next room

by measuring exceedingly tiny fluctuations in the

computer's radiation. The same technique can reveal which programs you're

using too. Every one of them has a different signature in electromagnetic field.

So I can tell which application you opened by looking into the spectrum.

The researchers quantified the signal available to eavesdroppers in a recent paper, presented

at the I- Tripoli AC.C.M. International Symposium on Micro Architecture

in the UK. Of course, real spies at the NSA and the CIA probably already know about this

trick, she says. But by alerting developers to the problem,

it might be possible to mask these electromagnetic leaks

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