The NSG During the Korean War

The Naval Security Group (NSG) was less involved in the Korean War than the Army Security Agency (ASA) or U.S. Air Force Security Service (USAFSS). As an NSA history of U.S. SIGINT activities has stated:
The DPRK had no blue-water navy, and [the NSG] was not concerned with the small collection of DPRK coastal patrol craft. The organization concentrated instead almost entirely on the Soviet navy in the Pacific, to determine what moves, if any, the Soviets would make toward the U.S. presence on the Korean Peninsula.