The National Security Agency is the Nation's cryptologic organization. NSA creates decisive U.S. strategic and tactical advantage by providing otherwise denied information to the U.S. decision makers while at the same time denying access to U.S. information and information systems by America's adversaries. The ability to understand the secret communications of our foreign adversaries while protecting our own communications - a capability in which the United States leads the world - gives our Nation a unique advantage. Signals Intelligence (SIGINT) and Information Assurance (IA) complement each other. SIGINT gives the Nation an information advantage over its adversaries. IA prevents other from gaining advantage over us. Together the two missions promote a single goal: information superiority for America and its allies.