Code breaking : a history and exploration / Rudolf Kippenhahn ; translated from the German, in collaboration with the author, by Ewald Osers. Verschlüsselte Botschaften. English Kippenhahn, Rudolf, 1926- Cryptography. Cryptography History. Z103 .K5613 1999 652.82 21 KIC Includes bibliographical references (p. [273]-275) and index. Woodstock, N.Y. : Overlook Press, 1999. 1999. 1999 Text 283 p. : http://www.loc.gov/catdir/toc/fy034/98048791.html eng eng ger