National Security Agency (NSA):

The NSA is a United States defense agency focused on collecting and analyzing foreign communications and foreign signals intelligence. As well, it protects the United States government communications and information systems with the use of cryptography. The vast majority of the NSA’s cryptographic products and algorithms are classified. As a result of its cryptologic superiority, the NSA is an integral component in supplying the nation with intelligence for counterterrorism and support to military operations.