This website could never be possible without many different sources and especially the kind help of several friends. I will try to enlist all people and sources, in no particular order, who helped me to make this website as informative and historically correct as it is now.


Frode Weierud
Prof. Tom Perera
David Hamer
Ralph Erskine
David Kahn
Jerry Proc
Craig Bauer
John Alexander
Tony Sale
Stefan Krah
Lech Maziakowski
Nicholas Gessler
Gudmundur Helgason
Paul Reuvers
Marc Simoens
Bob Lord
Martin Oberzalek
Morton Swimmer
Felix Shih
Toby Anderson
Andy Carlson
David Ross
Klaus Kopacz
Rebecca Ann Ratcliff

Special thanks to Graeme for his help in editing some of the English pages.

Papers & books related to Enigma

David H. Hamer, Geoff Sullivan and Frode Weierud, "Enigma Variations: an Extended Family of Machines," Cryptologia 1998

Louis Kruh and Cipher Deavours, "The Commercial Enigma: Beginnings of Machine Cryptography," Cryptologia, 2002

David P Mowry, "German Cipher Machines in Worl War II", Studies in Cryptology, NSA 2003

Commander Jerry C. Russell, US Navy, "Ultra and the campaign against the U-boats in World War II", Studies in Cryptology, NSA

Ralph Erskine, "Kriegsmarine short signal systems and how Bletchley Park exploited them", Cryptologia 1999

Chuck Roberts, "ULTRA in the Atlantic: U-boat operations", HyperWar Foundation, Special Research History NSA

Robert J. Hanyok, "Eavesdropping on Hell. Historical guide to Western, Communications Intelligence and the Holocaust, 1939-1945", Studies in Cryptology, NSA 2005

James Gillogly, "Ciphertext-Only Cryptanalysis of Enigma", Cryptologia 1995.

Ralph Erskine and Frode Weierud, "Naval Enigma: M4 and its Rotors", Cryptologia, 1987.

Ian Williams, "ULTRA in the Atlantic Volume IV: U-Boat Communications and U.S. Navy Communications Intelligence (Intercept and High Frequency Direction Finding), HyperWar Foundation, Special Research History NSA

David Hamer, "Enigma: Actions Involved in the Double Stepping of the Middle Rotor", Cryptologia 1997.

Heinz Ulbricht, "Die Chiffriermaschine Enigma: Trügerische Sicherheit: Ein Beitrag zur Geschichte der Nachrichtendienste", PhD Thesis, 2005

Tom Perera, "The Story of the ENIGMA: History, Technology and Deciphering"

Ralph Erskine, "Breaking Naval Enigma (Dolphin and Shark)"

Ralph Erskine, "Naval Enigma: Seahorse and other Kriegsmarine cipher blunders", Cryptologia 2004

Tony Sale, "The Bletchley Park translated Enigma Instructions Manual, transcribed and formatted", 2001

Tony Sale, "Enigma Officer and Staff Procedures 1940", 2001

David Kahn, "Seizing the Enigma", Houghton-Mifflin books, 1991

Michael Smith, "Station X", Channel 4 Books, 1998

Ralph Erskine, The Kenngruppenbuch Indicator System Used with the Main Wartime Naval Enigma Ciphers

Dr A. Ray Miller, "The Cryptographic Mathematics of Enigma", NSA

R. A. Ratcliff, "How statistics led the Germans to believe enigma secure and why they were wrong: Neglecting the practical mathematics of cipher machines", Cryptologia 2003


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