While the Navy has used codes and ciphers since its earliest days, not until the advent of radio communications did they become essential to successful operations. Thus, it was not until the beginning of the 20^th century that the Navy began systematic efforts to secure our own communications and exploit those of our adversaries.

In July 1922, the Navy formally established a cryptologic element, known as OP-20-G, which recognized that the future of cryptology lay in machine cipher systems, rather than in the manually operated strip ciphers that remained significantly unchanged since the 15^th century. Coupled with these efforts was the emergence of linguist specialists who translated the Japanese Navy Code.

During the period between the world wars, a handful of Navy and Marine Corps service members trained themselves in cryptologic procedures. The enlisted intercept specialists who trained on the roof of the old Navy Department building in Washington, DC, became known as the "On-the-Roof Gang" and were the core of the vastly expanded effort during World War II.

During the war, Navy cryptologists were successful in breaking the Japanese Naval Code, JN-15b, in time for the Battle of Midway, and were instrumental in providing information for the Fleet Commander to defeat the Japanese fleet. They also broke the Japanese merchant shipping code giving American submarines locations of Japanese ships. By war’s end, five-sixths of the Japanese merchant fleet were sunk, and their home islands were in danger of starvation.

In the Atlantic theater, Navy personnel operated the machines dedicated to deciphering the German Enigma-generated message traffic. By late 1943, most German radio communications were an open book to the Allies and the German submarine offensive had been defeated.

The war demonstrated the need for centralized management of signals intelligence while the trend toward increasingly complex technology and more sophisticated equipment continued. This culminated in the establishment of the Naval Security Group in 1950 and the National Security Agency in 1952.

Since the end of the war, the Naval Security Group has continued to support the signals intelligence effort in war, operations other than war, and during dangerous periods in peacetime. The FY-96 move of Headquarters to Fort George G. Meade brings even closer the relationship between the Group and the Agency. While the end of the Soviet Empire has changed the world, it still remains a dangerous place. The need for signals intelligence to support the fleet and the nation continues, and Commander, Naval Security Group, remains dedicated to that effort.

Commander, Naval Security Group Command (CNSG) (Source: FAS WebSite)

The Naval Security Group traces its origins back to the first days of electromagnetic communications in the early part of the century. The history of naval cryptology has a long tradition of service to the Navy and the nation.

The Navy has been concerned with protecting its signals against unauthorized use since the Civil War. More dramatic developments in cryptology came after the advent of radio communications in the Navy about the turn of the century. Beginning almost with the first wireless transmission from a Navy ship in 1899, Sailors and Marines have been assigned duties in communications security and intelligence. They conducted numerous experiments in this new field of warfare during World War I and dedicated themselves to drawing appropriate lessons from this experience in the years following.

The Code and Signal section of the Naval Communications Service undertook some cryptologic duties when the United States entered the war in 1917. In July 1922, it was assigned the familiar organizational title OP-20-G, which was retained until after World War II. Between 1924 and 1935, the Naval cryptology service developed operationally, culminating in the formation of the Naval Security Group effective 11 March 1935. That date marks the first appearance of the word "Group" in the title of the Naval cryptology organization and is observed as the birth of the Naval Security Group.

A handful of officers and small cadre of enlisted personnel trained themselves during the interwar period in the specific skills and knowledge of Naval signals exploitation and security. These pioneers formed the nucleus of the Communications Intelligence Organization during World War II. At the height of the war, nearly 10,000 naval specialists participated in the world-wide activities of the Naval Security Group. Their contributions played a role in all major campaigns of the war.

After 1945, the Navy was reduced in size and the consolidation of functions became necessary. The Navy Cryptologic organization was renamed Communications Supplimentary Activities in 1945 and the trend toward centralized control continued. Increasingly complex technology and more sophisticated equipment added new responsibilities and accelerated the movement toward career specialties in signal exploitation and security. In 1948, officer designators and enlisted ratings were established for cryptologic personnel. A closer alliance with Army and Air Force Cryptologists was formalized in 1949 with the establishment of the Armed Forces Security Agency. The title "Naval Security Group" was adopted in late 1950 and has remained the official name.

Naval Security Group personnel proved themselves in combat operations during the Korean conflict from 1950 through 1953. In 1952, the National Security Agency was created from the Armed Forces Security Agency, strengthening the bonds among service cryptologic elements. Experienced cryptologists who were veterans of both World War II and the Korean conflict continued to serve in the Naval Security Group throughout the decade of the 1950's. In 1956, the Naval Security Group Headquarters Activity was established, retaining the name until 1961 when it was redesignated the Naval Security Group Headquarters under the Director, Naval Security Group who assumed the title at the same time.

The eruption of hostilities in Southeast Asia and growing involvement of the United States Navy provided major impetus to the expansion of Naval signals exploitation and security in the 1960's. On 1 July 1968, the Naval Security Group Command was established under a flag officer. In March 1971, a reorganization within the Office of the Chief of Naval Operations formed the Signals Exploitation and Security Division; marking the separation of Cryptology from Communications for the first time in 50 years. The Commander, Naval Security Group Command is now assigned additional duty in the Office of the Chief of Naval Operations as the Deputy Director of Naval Intelligence. The Naval Security Group Command and Naval cryptologists serving world-wide exist for the sole purpose of supporting Naval and national operations which provide for and ensure the defense of the United States.