<p>Seal of the United States <a href="https://en.wikipedia.org/wiki/National_Security_Agency" class="extiw" title="en:National Security Agency">National Security Agency</a>, used between 1963 and 1966 before being replaced by the current seal.
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The NSA was formed in 1955, but did not have its own seal for several years.  This seal was first used in February 1963, before being replaced in September 1966 with the seal used today.  The NSA has no information on the origin or design of this seal.  For more information, see <a rel="nofollow" class="external text" href="http://www.nsa.gov/cch/cch00003.cfm">here</a>.
U.S. Government
NSA seal history <a rel="nofollow" class="external text" href="http://www.nsa.gov/cch/cch00003.cfm">page</a> (direct image URL <a rel="nofollow" class="external autonumber" href="http://www.nsa.gov/cch/images/image00001.jpg">[1]</a>).