Browse Prior Art Database

The Autoscritcher and the Superscritcher: Aids to Cryptanalysis of the German Enigma Cipher Machine, 1944-1946

IP.com Disclosure Number: IPCOM000129752D
Original Publication Date: 1992-Sep-30
Included in the Prior Art Database: 2005-Oct-07
Document File: 19 page(s) / 69K

Publishing Venue

Software Patent Institute

Related People

DAVID J. CRAWFORD: AUTHOR [+3]

Abstract

[Footnote] * David Crawford succumbed to cancer i O days after the original manuscript for this article was mailed to the Annals As another member of the Scritcher group, and as a friend of over A) years, I have acted as editor since his death, to see his project to completion. Without Dave's detailed memory and his desire to get the story of the Scritchers recorded there would have been no article None of the rest of us could remember enough. This article has been cleared for publication by the National Security Agency. but its contents are the sole responsibility of the author and me.-- Philip E. Fox LS IEEE

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 5% of the total text.

Page 1 of 19

THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

Copyright ©; 1992 by the American Federation of Information Processing Societies, Inc. Used with permission.

The Autoscritcher and the Superscritcher: Aids to Cryptanalysis of the German Enigma Cipher Machine, 1944-1946

DAVID J. CRAWFORD

PHILIP E. FOX (EDITOR)*

1

At the US Army Signal Security Agency during World War 11, two systems were built to assist cryptanalysts in breaking messages enciphered on Enigma-type machines. Called the Autoscritcher, the first machine used relay technology. The final system, the Superscritcher, was fully electronic and contained about 3,500 vacuum tubes. Both machines operated successfully. The system approach in both machines was the same, but differed from that of the "Bombe" mechanical machines in use to do a similar job. The Superscritcher proved the practicality of electronic digital technology for computing applications. It also showed, however, that a more flexible architecture was needed to enable the solving of more than one class of problems.

Categories and Subject Descriptors: K.2 [Computing Milieux]: History of Computing -- Hardware, People. E.3 [Data]: Encryption. General Terms: Design. Additional Terms: Enigma, Cryptanalysts, Autoscritchers, Superscritchers, Scatchers, Bombes, Code Breaking.

In recent years the British government has declassified Much of its World War II activity in the field of cryptanalysis. The earlier publications to appear) 2 were concerned with the organizational and operational aspects of the work and included some cursory descriptions of the Enigma cipher machine, the principal encrypting device used by all three German military services.

Later publications3-6 include a more detailed technical description of the Enigma, as well as of the "Bombes," mechanical machines that were essential aids to the Allied cryptanalysts who were reading Enigma traffic. In addition, Kahn's books covers the different ways the Enigma was used by the German Air Force, Army, and Navy, and the effect these ways had on the difficulty encountered in the breaking of messages of the three organizations. Although not concerned with the Enigma, the Colossus was a British electronic cryptanalytic machine of the same era.7,8

To date, very little technical detail has been published about the World War 1I cryptanalytic activity that occurred in the United States. What material has been released has been broadbrush descriptions of the operational aspects. For example, it is now public knowledge that the United States was successful in breaking several Japanese codes and ciphers, including the Japanese version of the Enigma machine, but the author is not aware of technical details having been published.

1 * David Crawford succumbed to cancer i O days after the original manuscript for this article was mailed to the Annals As another member of the Scritcher group, and as a friend of over A) years, I have acted as editor since his deat...