COMPUTER MEMORIES, Chapter 69

READING RADIO WAVES FROM A COMPUTER
Did you know that some one could park a truck on the street just outside your house and make a copy of everything that happens on your computer? Everything the computer does, including key strokes, and data transfers, generate radio waves, just like a variable light switch generates noise in your radio.

In the late 1950s some one had tried to tell the management of a large computer system (containing some kind of sensitive information) in Washington DC, that they should be concerned that their data might not be all that secure. It was known (approximately) that at 10:00 AM on Tuesday, all the data in that computer was copied from one magnetic tape to another as “back-up” in case of a problem. At a few minutes before 10:00 a panel truck parked near the computer building, and a few hours later a printout of the “secure” data was delivered to the computer facility in question! Now they believed!

Trivia, but true: The CIA Agent Spy (Ames), who was discovered a few years ago, was discovered, at least in part, by a truck parked a block from his house with a device listening to the signal made by the keys on his computer.

Fifty years ago some of the Air Defense Computers were located in caves in mountains in Colorado. Those computer systems were completely surrounded with copper mesh, with copper mesh “double door locks” to make sure that at no time was there an opening from the outside to the computer. The copper mesh stopped transmission of radio waves. They were concerned that it was possible for some one to copy the computer program that was used to control the Air Defense System, and that a truck with the proper equipment could park somewhere outside the cave, keep track of what the computer was doing, and at the proper point in the program, change the identification of an aircraft from “hostile” to “friendly” and change a critical decision on the part of the people in charge.