Lieutenant Commander Philip H. Jacobsen, U.S. Navy (Retired), is a researcher, columnist, and indexer for the U.S. Naval Cryptologic Veterans Association's journal, The Cryptolog. He enlisted in the Navy in June 1941 and retired after more than 28 years of service, 27 of those years serving with the Naval Security Group or its predecessor organizations. In World War II, he served as an intercept and direction finder operator as well as an analyst on Japanese naval and naval air communications.
