Notes - Burdens of Proof - page 197

41. The system is “pseudorandom” insofar as it consists of a deterministic algorithm
that outputs a sequence of numbers that appears random to the adversary. See
Menezes, van Oorschot, and Vanstone, Handbook of Applied Cryptography , chapter 5.
42. A remarkable case of reverse engineering, as the codebreakers never set eyes on
an actual Lorenz cipher until the end of the war. See Copeland, Colossus .
43. Claude E. Shannon, “Communication Theory of Secrecy Systems,” Bell System
Technical Journal 28, no. 4 (1949), 659. This companion paper to “A Mathematical
Theory of Communication” was published but classified in 1946 and declassified in
1949. In an interview with Kahn, Shannon explained, “The work on both the math-
ematical theory of communications and the cryptology went forward concurrently
from about 1941. I worked on both of them together and I had some of the ideas
while working on the other. I wouldn't say one came before the other—they were
so close together you couldn't separate them.” Kahn, The Codebreakers , 744.
44. Gustavus J. Simmons, “Contemporary Cryptology: A Foreword,” in Contempo-
rary Cryptology: The Science of Information Integrity , ed. Gustavus J. Simmons (Piscat-
away, NJ: IEEE Press, 1992), 11.
45. Shannon, Communication Theory of Secrecy Systems , 656.
46. Kahn, The Codebreakers , 515.
47. Horst Feistel, “Cryptography and Computer Privacy,” Scientific American 228,
no. 5 (1973): 15-23.
48. Ibid., 2-3.
49. Shannon, Communication Theory of Secrecy Systems , 708-710.
50. Stinson, Cryptography: Theory and Practice , 83.
51. See James Bamford, The Puzzle Palace: A Report on America's Most Secret Agency
(New York: Penguin Books, 1983), and Bamford, Body of Secrets , for a history and
description of the NSA. To write about the NSA in the early 1980s, at a time when
it was almost impossible to obtain any information about the agency (the NSA was
exempt from FOIA requirements), Bamford had recourse to various investigative
strategies, including traffic analysis in its most literal form: “Curious as to whether
the cooperation [with British and Canadian intelligence agencies] was ongoing,
Bamford took a drive through the parking lot outside of NSA headquarters, taking
down the license plate numbers of cars that, based on their proximity to the build-
ings, were likely to belong to top officials. He noticed two vehicles with diplomatic
plates. A trace revealed they belonged to an Englishman and a Canadian.” Paul
Constance, “How Jim Bamford Probed the NSA,” Cryptologia 21, no. 1 (1997): 73.
52. The DES standardization process and the controversy that accompanied it have
been extensively chronicled—see, for example, Miles E. Smid and Dennis K. Branstad,
“The Data Encryption Standard: Past and Future,” Proceedings of IEEE 76, no. 5 (1988):