National Security Agency/Central Security Service is a high-technology agency within the United States Department of Defense. The agency, sometimes called the NSA/CSS, has two primary missions: (1) information assurance and (2) signals intelligence. Information assurance seeks to ensure the security of classified and sensitive information and systems within the U.S. government. Signals intelligence involves the gathering, analysis, and handling of secret information transmitted by foreign countries. The responsibilities of the NSA/CSS include both military and nonmilitary matters.