Telecommunication has never been perfectly secure, as a Cold War culture of wiretaps and international spying taught us. Yet many still take their privacy for granted, even as we become more reliant on telephones, computer networks and electronic transactions of all kinds. Many of our relationships now use telecommunication as the primary mode of communication that the security of these transactions has become a source of wide public concern and debate. The authors argue that if we are to retain the privacy that characterized face-to-face relationships in the past, we must build the means of protecting that privacy into our communications systems. However, the development of such protection is not easy. The US government uses strong export control to limit the availability of cryptography within the United States and bills introduced in 1997 place legal restrictions on the essential elements of any secure communications system. These policies attempt to limit encryption to forms that provide a "backdoor" for government wiretapping. This book aims to strip away the hype surrounding the policy debate to examine the national security, law enforcement, commercial and civil liberties issues. It discusses the social function of privacy, how it underlies a democratic society and what happens when it is lost. The book also explores the workings of intelligence and law enforcement organizations, how they intercept communications and how they use what they intercept.