The art and science of code-making and code-breaking is driven both by the risk inherent in an adversary's ability to read an intercepted communication and the technology available to mitigate that threat efficiently and cost-effectively. This is true both for today's computer-driven cryptography and cryptanalysis and the simpler, yet no less vital codes and ciphers used in the past. In "Masked Dispatches: Cryptograms and Cryptology in American History, 1775-1900," the beginnings of American cryptography are portrayed as rooted in the nation's origin in revolutionary conspiracy. Although the...

For more than 30 years, the Vietnamese revolutionary movement successively fought Japan, France, South Vietnam, and the United States of America in its successful struggle to establish an independent and socialist Vietnam. Although many aspects of these wars have been described and analyzed by both the winners and losers, one significant topic has been almost entirely absent from the discussion - the Vietnamese development and use of cryptography to maintain their movement's communications security. "Essential Matters: A History of the Cryptographic Branch of the People's Army of Viet-Nam,...