Skip navigation
Hardcover | $7.75 Short | £6.95 | 496 pp. | 6 x 9 in | March 2007 | ISBN: 9780262042406
Paperback | $31.95 Trade | £26.95 | 496 pp. | 6 x 9 in | February 2010 | ISBN: 9780262514002
eBook | $22.95 Trade | February 2010 | ISBN: 9780262251402
Mouseover for Online Attention Data
Open Access IconThis is an open access title

Look Inside

Privacy on the Line, Updated And Expanded Edition

The Politics of Wiretapping and Encryption


Telecommunication has never been perfectly secure. The Cold War culture of recording devices in telephone receivers and bugged embassy offices has been succeeded by a post-9/11 world of NSA wiretaps and demands for data retention. Although the 1990s battle for individual and commercial freedom to use cryptography was won, growth in the use of cryptography has been slow. Meanwhile, regulations requiring that the computer and communication industries build spying into their systems for government convenience have increased rapidly. The application of the 1994 Communications Assistance for Law Enforcement Act has expanded beyond the intent of Congress to apply to voice over Internet Protocol (VoIP) and other modern data services; attempts are being made to require ISPs to retain their data for years in case the government wants it; and data mining techniques developed for commercial marketing applications are being applied to widespread surveillance of the population.

In Privacy on the Line, Whitfield Diffie and Susan Landau strip away the hype surrounding the policy debate over privacy to examine the national security, law enforcement, commercial, and civil liberties issues. They discuss the social function of privacy, how it underlies a democratic society, and what happens when it is lost. This updated and expanded edition revises their original—and prescient—discussions of both policy and technology in light of recent controversies over NSA spying and other government threats to communications privacy.

About the Authors

Whitfield Diffie, the inventor of public-key cryptography, is Visiting Professor at Royal Holloway College at the University

of London.

Susan Landau is Bridge Professor in the Fletcher School of Law and Diplomacy and the School of Engineering, Department of Computer Science, at Tufts University. She has been a Senior Staff Privacy Analyst at Google, a Distinguished Engineer at Sun Microsystems, and a faculty member at Worcester Polytechnic Institute, the University of Massachusetts Amherst, and Wesleyan University. Landau has been a Guggenheim fellow and a fellow at the Radcliffe Institute for Advanced Study, and is a member of the Cybersecurity Hall of Fame, a fellow of the American Association for the Advancement of Science, and a fellow of the Association for Computing Machinery.


“A compact and intelligible guide to both the technical and the political issues.”—Laurence A. Marschall , The Sciences
“A superb and timely introduction to a subject of enormous importance for scholars and citizens alike.”—Choice
“A well-researched and fascinating study.”—Lawrence Rothstein, Law and Politics Review
“A wise, meticulously researched guide....”—London Review of Books
“An incredibly comprehensive insight into the world of encryption and wiretaps, its political machinations, legal aspects, technologies, vulnerabilities, costs, limitations, and near-ubiquity.”—G. Ernest Govea, Security Management
“Diffie and Landau deserve a large audience. Their lucid exposition adds valuable context to debates that for too long have been abstract.”—Aziz Huq, The American Prospect
“Should be required reading for any computing student at any level.”—Harold Thimbleby, New Scientist
“The book details numerous privacy issues, from personal privacy to national security.... A welcome surprise is that the book often reads like a Tom Clancy novel, interwoven as it is with episodes of domestic and international intrigue.... A timely and important book.”—Ben Rothke, Security Management
“[A] wise, meticulously researched guide...”—London Review of Books
“Should be required reading for any computing student at any level.”—Harold Thimbleby , New Scientist


Awarded the 1998 Donald McGannon Award for Social and Ethical Relevance in Communication Policy Research.