Fisher swiveled around in his chair and looked at the puzzled attorney.
“All electrical current produces a magnetic field, thus computers emit
magnetic fields, relatively strong ones. These transmissions can be
easily captured and recorded. On top of it, computers also give off
digital impulses. This CRT”–Fisher pointed at his computer
monitor–“throws off clear video images if you have the right receiving
equipment, which is widely available. I could drive through downtown
D.C. with a directional antenna, a black-and-white TV and a few bucks’
worth of electronic parts and steal the information off every computer
network in every law firm, accounting firm and government facility in
the city. Easy.”
Sidney was incredulous. “You’re saying if it’s on someone else’s screen
you can see it? How is that possible?”
“Simple. The shapes and lines on a computer screen are composed of
millions of tiny dots called picture elements–or pixels, for short.
When you type in a command, electrons are fired at the appropriate spot
on the screen to light appropriate pixels–like painting a picture.
The computer screen must be continually refreshed with electrons to keep
the pixels lit. Whether you’re playing a computer game or doing word
processing or whatever, that’s how you can see things on your screen.
You with me so far?” Sidney nodded.
“Okay, each time electrons are shot at the screen, they give off a
high-voltage pulse of electromagnetic emission. A TV monitor can
receive these pulses pixel by pixel. However, since an ordinary TV
monitor can’t adequately organize these pixels to reconstruct what’s on
your screen, an artificial synchronization signal is used so the picture
can be exactly reproduced.”
Fisher paused to look at his computer again and then continued.
“Printer? Fax? Same thing. Cellular phones? Give me one minute with
a scanner and I can have your internal electronics serial number, or
ESN, your cell phone number, your station class data and the phone’s
maker. I program that data into another cell phone with some
reconfigured chips, and I start selling long-distance service and charge
it to you. Any information that flows through a computer, either
through the phone lines or through the air, is fair game.
And what doesn’t these days? Absolutely nothing is safe.
“You know what my theory is? Pretty soon we’ll stop using computers
because of all the security problems. Go back to typewriters and ‘snail
mail.””
Sidney looked puzzled.
“Snail mail is a techie’s derogatory term for the U.S. mail. They may
get the last laugh, though. Mark my words. That day is coming.”
A sudden thought entered Sidney’s head. “Jeff, what about regular
phones? How could it be that I call a number, say my firm number, and
someone answers who I know for a fact cannot be at my firm?”
“Somebody hacked into the switch,” Fisher said immediately.
“The switch?” Sidney looked completely bewildered.
“It’s the electronics network over which all communications from pay
phones to cellular phones travel across the United States. If you hack
into it, you can communicate with impunity.” Fisher turned back to his
computer. “However, with all that said, I’ve got a really good security
system on my computer, Sid.”
“Is it completely foolproof? No one could break it?”
Jeff laughed. “I don’t know anyone in their right mind who could make
that claim, Sidney.”
Sidney looked at the disk, wishing she could just tear pages out of it
and read them. ‘Tm sorry if I sound paranoid.”
“No sweat. No offense, but most lawyers I know are borderline paranoid.
They must have a class in law school on it or something.
But we can at least do this.” He unplugged the phone line from his CPU.
“Now we’re officially off-line. I have a first-rate virus sweeper on
this system, in case anything got on previously. I just ran a check, so
I think we’re safe.”
He motioned Sidney to sit down. She slid a chair around and they both
studied the screen. Fisher hit a series of keys and a directory of the
files on the disk appeared. He looked over at Sidney. “About a dozen
files–from the number of bytes listed I’d say about four hundred or so
pages if it’s standard text. But if there are a lot of graphics there’s