This oral history was originally completed in 1970 and then was confiscated by the Navy the following year. It was subsequently classified secret by the National Security Agency because of its discussion of codebreaking. A sanitized version, with classified material removed, was released by NSA in late 1982 and forms the basis for this new volume, which contains probably at least 95% of the original. Captain Rochefort is best known for leading the team of codebreakers at Pearl Harbor which produced information instrumental in the U.S. victory at the Battle of Midway in June 1942. He discusses that in the context of an overall career which included a good deal of service on board ships and operational staffs, including that of Commander in Chief U.S. Fleet. He discusses the beginnings of U.S. Navy cryptanalysis and his own study of the Japanese language. During World War II, he got sidetracked from intended billets by the controversies over the Midway Battle and the attack on Pearl Harbor. At war's end, he participated in a strategic intelligence survey and was later recalled to active duty to study various battles.