NSA Center for Cryptologic History
From the site: "At the CCH, we believe learning from the past can help improve future decision making. Through the National Cryptologic School (NCS), we offer numerous learning opportunities for intelligence professionals. These include a variety of history courses, seminars, illustrated lectures, and case studies. Our many publications, classified and unclassified, document the past and enable today's cryptologic professionals to benefit from a historical perspective as they tackle increasingly challenging missions."