yardley feature

NSA.gov: Herbert O. Yardley

Congress Discusses Regulating the Publishing Industry

By June 10, 1933

After former State Department codebreaker Herbert Yardley publishes his book “The American Black Chamber,” recounting the history of American codebreaking and signals security, Congress debates the regulation of the publishing industry in order to protect national security.

In 1948, Congress bans federal employees from publishing any information originally transmitted in foreign code.

When Yardley tried to publish his second book, “Japanese Diplomatic Codes: 1921-1922,” the manuscript was seized by U.S. marshals.