The National Security Council Intelligence Directive (NSCID) No. 9, signed by U.S. president Harry S. Truman on October 24, 1952, established the National Security Agency (NSA). A separate and extremely secretive agency within the Department of Defense, headquartered at Fort George G. Meade, Maryland, the NSA is a cryptologic organization, the world's best at making and breaking codes and ciphers, as well as one of the leading centers of foreign-language analysis within the U.S. government. Neither the number of employees nor the agency's budget can be publicly disclosed, but some analysts estimate that its yearly budget is as high as $10 billion. The NSA does not disclose sources or methods of intelligence and never comments on media speculations about actual or possible intelligence issues.

The agency's civilian and military employees include physicists, engineers, mathematicians, analysts, computer scientists, and linguists. They are charged with two sensitive ...