Preface

HORTENSIO: Madam, before you touch the instrument
To learn the order of my fingering,
I must begin with rudiments of art
To teach you gamouth in a briefer sort,
More pleasant, pithy and effectual,
Than hath been taught by any of my trade;
And there it is in writing, fairly drawn.

—The Taming of the Shrew, III, i, 62–68.

On September 11, 2001, terrorists seized control of four airplanes. Three were flown into buildings, and a fourth crashed, with catastrophic loss of life. In the aftermath, the security and reliability of many aspects of society drew renewed scrutiny. One of these aspects was the widespread use of computers and their interconnecting networks.

The issue is not new. In 1988, approximately 5,000 computers throughout the Internet were rendered unusable within 4 hours by a program called a worm [432].^[1] While the spread, and the effects, of this program alarmed computer scientists, most people were not worried because the worm did not affect their lives or their ability to do their jobs. In 1993, more users of computer systems were alerted to such dangers when a set of programs called sniffers were placed on many computers run by network service providers and recorded login names and passwords [374].

^[1] Section 22.4 discusses computer worms.

After an attack on Tsutomu Shimomura's computer system, and the fascinating way Shimomura followed the attacker's trail, which led to his arrest [914], the public's interest and apprehension were finally aroused. Computers were now vulnerable. Their once reassuring protections were now viewed as flimsy.

Several films explored these concerns. Movies such as War Games and Hackers provided images of people who can, at will, wander throughout computers and networks, maliciously or frivolously corrupting or destroying information it may have taken millions of dollars to amass. (Reality intruded on Hackers when the World Wide Web page set up by MGM/United Artists was quickly altered to present an irreverent commentary on the movie and to suggest that viewers see The Net instead. Paramount Pictures denied doing this [448].) Another film, Sneakers, presented a picture of those who test the security of computer (and other) systems for their owners and for the government.