Selecting a birthdate for the Naval Security Group was somewhat like trying to determine when several people had the same thoughts at the same time. The Naval Security Group was not born on one particular day and promulgated by an official directive; it was born in men’s minds and finally culminated in an organization with official status.

Historically, the Naval Security Group began in 1916 when the Code and Signal Section, under an officer in charge, was established in the Office of the Chief of Naval Operations. In 1918 our first modern codes were issued. They were copied after British codes used by us during World War I. After the Armistice was signed, “an intelligence clerk from the Cable Censor’s Office was transferred to the Code and Signal Section for research work in the development of codes and ciphers.” This was the beginning of communications intelligence research. It became apparent at once that in order to learn the weakness of codes and ciphers, and hence how to construct secure ones, the first essential was to learn to solve them (cryptanalysis).

In 1923 the officer in charge of the Code and Signal Section did not have the knowledge to pursue cryptanalysis and in January 1924, the Research Desk within the Code and Signal Section was established with one officer, one cryptanalyst, and two typists. The Research Desk was concerned with research, training, U. S. Naval systems, intercept, work on foreign systems, and, other requirements.

The Navy has been engaged in RDF (radio direction finding), as it was then known, since World War I. In 1917 and 1918 the Navy Department established a system of medium frequency RDF stations along the Atlantic Coast for tracking German submarines operating in the Western Atlantic. In 1922, and again in 1924, SECNAV stated that the primary purpose of the “radio compass” system was the location and tracking of enemy vessels in time of war. SECNAV allowed these RDF stations to service the merchant marine in the 1920’s so that the naval personnel assigned to them could acquire proficiency in their work. In 1924 the Navy had 52 RDF stations either in operation or under construction.

There is no evidence that the Navy engaged in radio intercept during World War I. But the Navy definitely has been engaged in radio intercept since the early 1920’s. In 1923 ONI requested that all ships of the Asiatic Fleet forward intercepted Japanese and commercial code messages. In 1924, and possibly before, the Naval Radio Station at the Navy Purchasing Office, Shanghai, China, was intercepting and forwarding Japanese traffic. In 1924 the Naval Radio Station, San Francisco was forwarding “all official Japanese traffic” to the Code and Signal Section and in that same year the first Navy intercept station was established in the U. S. Consulate, Shanghai. In early 1926 the: Code and Signal Section consisted of four desks: (1) Registered Publications, (2) Visual, (3) Code and Cipher, and (4) Research. An organizational chart of 1 July 1926 shows that Registered Publications became a separate section, Op-20-P. It remained thus until 1950.

In early 1935, in accordance with joint action of the Army and Navy, radio intelligence was determined to be a function of communications and the Navy portion of radio intelligence was assigned to the Office of Naval Communications. On 11 March 1935, Op-20G became the “Communications Security Group”. This date commemorates the birth of the Naval Security Group. The 1935 organization was as follows:

Op-20G Communications Security Group
GC Cryptographic Section
GS Communications Security
GX Radio Intercept and Tracking
GY Cryptanalytic Section
GZ Translation Section

Since that time the organization has varied slightly at times. In 1942 the Communications Security Section and the Cryptographic Section became Op-20K and Op-20Y, respectively. At the same time, however, Op-20G expanded into 17 subsections. Op-20G also became an Assistant Director for Communications Intelligence. The establishment of the Assistant Director coincided with the inclusion of all COMINT functions, including direction finding, under one office of DNC.

In 1942 it became apparent that additional space and additional, security were needed for greater operating efficiency. The site at 3801 Nebraska Avenue was acquired and on 7 February 1943, Op-20G moved from the Navy Department to the Communications Supplementary Annex.

The Annex was officially established as a shore activity on 1 July 1948 and renamed the Naval Communications Station_ Washington. The commanding officer of the station also had the title of Officer in Charge, CSAW (Communications Supplementary Activity, Washington). He had the dual function of exercising military command and coordination control, under the Commandant, Potomac River Naval Command, of all activities located at the Communications Station, and, in addition, of directing the operation of CSAW in accordance with directives of CNO (Op-20-2) so as to carry out efficiently the tasks assigned. The work of CSAW was: traffic analysis, cryptanalysis, cryptanalytic research, radio research, analytical research, and training of CSAW personnel.

On 28 January 1950, the following functional organizations were designated the Navy Security Group: (1) Communications Supplementary Activities, (2) Communications Supplementary Detachments, (3) Communications Security Activities, (4) Special Electronics Search Projects.

In June 1950, the Registered Publication Section was added. By this action all of the functions of COMINT, ELINT, and COMSEC came under one head. In September 1950, the Naval Communication Station was redesignated the Navy Security Station. In 1953 the organization, now designated the Naval Security Group, included Communication Units, Security Group Departments, Naval Security Detachments, and RPIO’s. In 1956, the U. S. Naval Security Group Headquarters Activity, under an officer in charge, was established. In 1961 it was redesignated Naval Security Group Headquarters under the Director, Naval Security Group. Functions formerly performed by the officer in charge and those performed by Head, Naval Security Group as a member of the staff of the Director, Naval Communications, were consolidated under the Director, Naval Security Group, who administered and directed the operations of the Naval Security Group and exercised management control of the component activities of the Naval Security Group.

When the Naval Communications Command was activated in 1967, the Chief of Naval Operations delegated command and primary support of the Naval Security Group to the Commander, Naval Communications and the Director, Naval Security Group also became the Deputy Commander for Cryptology, Naval Communications Command.

The Naval Security Group Command, under a Commander reporting directly to the Chief of Naval Operations, was activated 1 July 1968. Simultaneously the Headquarters, Naval Security Group Command was established and assigned to the Chief of Naval Operations for command and support. The Naval Security Group Command comprises the Headquarters and assigned shore (field) activities. The Commander, Naval Security Command is assigned additional duty to the Chief of Naval Operations as Executive Assistant for Cryptology in the office of the Assistant Chief of Naval Operations (Communications and Cryptology).