Elizebeth Friedman’s security and career concerns prior to World War II

Much has been written about Elizebeth Friedman’s codebreaking that busted rum runners during Prohibition in the United States. Recently, declassified documents, as well as other research, demonstrate that as her Coast Guard cryptanalysis unit headed toward World War II, she (as well as naval authorities) developed concerns that publicity regarding her unit’s abilities would tip off America’s enemies and harm national security.