[From "Homeland Insecurity," by Charles C. Mann]

[From "Homeland Insecurity," by Charles C. Mann]

For clear primers on modern cryptography and on network security, it is hard to do better than Bruce Schneier's Applied Cryptography (1993) and Secrets and Lies (2000), respectively; these books (especially the latter) render technological arcana comprehensible to even the willfully Luddite. The consensus classic in the field of cryptology remains The Codebreakers: The Story of Secret Writing (1967), by David Kahn. Kahn spent four years working on a book that sought, in his words, "to cover the entire history of cryptology." (That is in fact a modest description of a 1,200-page book that begins with a chapter called "The First 3,000 Years" and closes, twenty-five chapters later, with "Messages From Outer Space.") All subsequent chroniclers of cryptography unavoidably stand on Kahn's shoulders. But The Codebreakers nearly died aborning: reportedly, the Pentagon tried to suppress its publication; only after Kahn agreed to delete three passages was the book finally published. Kahn issued a new edition of the book in 1996, bringing his history nearly up to the century's end. Two of the most relevant books on the subject of homeland security, both published in 1998, were also the most prescient. Terrorism and America: A Commonsense Strategy for a Democratic Society, by Philip B. Heymann, and America's Achilles' Heel: Nuclear, Biological, and Chemical Terrorism and Covert Attack, by Richard A. Falkenrath, Robert D. Newman, and Bradley A. Thayer, warned of the imminent danger of a major terrorist attack on American soil. Although the proposed Department of Homeland Security was hastily thrown together, the idea for such an entity had circulated within the government for years. Some of the proposals can be found in the excellent compilation of disparate reports that the U.S. Senate Committee on Foreign Relations put together last fall, when it was preparing for hearings on the subject of national security. The compilation is called Strategies for Homeland Defense and is available on the Internet at purl.access.gpo.gov/GPO/LPS15541.