Intended for the interception (and decryption if possible) of foreign communications, the NSA has been heavily involved in research into cryptology, crediting the breaking of World War II Japanese codes to a predecessor organization's team of cryptographers. The NSA is also responsible for assisting in securing the U.S.'s governmental, military, and even private (to some extent) communications infrastructure from the efforts of agencies like itself working for foreign powers.

For instance, the agency recommended changes to the IBM submission to NIST during the process which produced the DES encryption algorithm in the first half of the 1970s. Subsequently, it was widely believed that those changes were made so as to make it easier for the NSA to break the cypher when desired. However, the public rediscovery of differential cryptanalysis showed that one of the changes were actually likely to have been suggested to harden the algorithm against this cryptanalytic technique not then publicly known. It remained publicly unknown until Biham and Shamir idependently discovered it and published some decades later. However, the shortening of the 112-bit key used by the IBM submission to an effective 56 bits has never been explained as anything other than a weakening of the algorithm.

The NSA, in combination with corresponding agencies in the United Kingdom (GCHQ), Canada, Australia (the Defence Signals Directorate), and New Zealand, is believed to be responsible for, among other things, the operation of the Echelon system, whose capabilities are suspected to include the ability to monitor a large proportion of the civilian phone and data traffic transmitted around the world. The scale of these efforts is hard to determine from unclassified data, but one strong clue is the electricity usage of the NSA headquarters. The NSA's budget for electricity exceeds $21 million per year, making it the second largest electricity consumer in Maryland. Using conservative estimates, the NSA headquarters alone uses enough electricity to power four Earth Simulators (as of 20 Sept 2002, the most powerful supercomputer in existence).

Many people oppose the NSA, saying that the NSA infringes on americans' right to privacy by spying on the United States' own citizens; others say that the NSA doesn't exist at all, noting that NSA could also stand for No Such Agency.

History
The predecessor of the NSA, the Armed Forces Security Agency (AFSA), was established within the Department of Defense, under the command of the Joint Chiefs of Staff, on May 20, 1949. The AFSA was to be responsible for directing the communications and electronic intelligence activities of the military intelligence units - the Army Security Agency, Naval Security Group and the Air Force Security Service. However, the agency had little power and lacked a centralized coordination mechanism. After an extensive study authorized on December 13 1951, the NSA was created in June 1952.

Headquarters for the NSA is Fort George G. Meade, Maryland.

Further reading
James Bamford - Body of Secrets, 2001, Doubleday, ISBN 0-385-49907-8
James Bamford - The Puzzle Palace

External links
NSA official site

Fort George G. Meade, Maryland, is a semi-active Army installation. It was used as a basic training post and a prisoner of war camp during World War II. In the 1950s, the post became headquarters of the National Security Agency.

The post was scheduled for closing in the 1990s, but was kept open because of the requirements of the NSA.

Since the terrorist attacks of September 11, 2001, security on the post has been tightened considerably.

The post is also used for the Department of Defense school of public affairs.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "NSA".