M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception The History and Technology of the Enigma Cipher Machine M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception Ralph Simpson Ralph@CipherHistory.com  Copyright © 2019 CipherHistory.com

US Army M-94 Cipher Device M-94 Cylinder Cipher US Army M-94 Cipher Device Main US battlefield cipher device, 1922-43 25 wheels, each with a unique mixed alphabet Plaintext arranged on ruler, user selects another row as ciphertext Key is the order of wheels on axle, labeled inside B-1 to Z-25 Key space very large, (# wheels)! 25! = 83 bit key, greater than Enigma or DES “Multiplex” cipher, multiple simultaneous vs. serial ciphers – coined by William F. Friedman M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

The History and Technology of the Enigma Cipher Machine Quiz What do the following ciphers have in common? Cylinder cipher One time pad Enigma machine Public key encryption Vigenère cipher Wheatstone cipher Playfair cipher Cylinder – Thomas Jefferson in 1795, not Bazeries in 1891 One-time pad – Frank Miller in 1872, not Gilbert Vernam and Joseph Mauborgne in 1917 Enigma – Dutch sailors Rudolf Spengler and Theo van Hengel in 1915, not Arthur Scherbius in 1918 Public Key Encryption - James Ellis, Malcolm Williamson and Clifford Cocks of the UK GCHG in 1973, not Whitfield Diffie and Martin Hellman in 1976 and Ron Rivest, Adi Shamir, and Leonard Adleman in 1978 Vigenere – Leon Batista Alberti in 1467, not Blaise de Vigenere who was born 56 years later Wheatstone – Decius Wadsworth in 1817, not Charles Wheatstone in 1850s Playfair – Charles Wheatstone in 1854, not Lord Playfair, a friend of Wheatstone who advocated its use They were all originally credited to the wrong inventor! M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

1st Invention of Cylinder Cipher Thomas Jefferson – yes, our third President! Invented “Wheel Cypher” c.1795 Only one known to exist, in NSA Museum Uses 36 wheels, Jefferson correctly calculated key space as “372 with 39 cyphers [zeros] added to it” Jefferson Wheel Cypher Inspiration may have been Chinese letter locks, popular in France at the time Wheel Cypher lost to history until discovered in Jefferson’s papers in Library of Congress in 1922, by Dr. John M. Manly M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

2nd Invention of Cylinder Cipher Etienne Bazeries French Army Maj. invention in 1891 20 wheel cipher Probably not aware of previous Jefferson invention, but would have been aware of letter locks Broken by Gaetan de Vaires in 1893, so it was Bazeries Cylinder not adopted by the French military Bazeries previously solved a de Vaires cipher M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

3rd Invention of Cylinder Cipher Parker Hitt Hitt did not know of the Jefferson or Bazeries inventions Lt. James G. Taylor, a classmate in 1911, made a cylinder and strip device to decipher the Army Cipher Disk Parker Hitt’s first cylinder device, Feb. 1912 In Feb. 1912, Hitt developed a device for deciphering Army cipher disks using 12 pairs of wheels One of each pair had mixed alphabets, which were on a single shaft in the shop when Hitt noticed a “TH” on first 2 disks… that was the inspiration for the M-94 Hitt invented both the cylinder and strip cipher device, but decided to pursue the strip version M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

Strip Cipher Parker Hitt pursued the strip cipher version, first deployed in 1934 (M-138) but used earlier for cryptanalysis Cryptologically identical to cylinder cipher Used 25 strips of mixed alphabets, later M138-A used 30 strips 1916 Hitt Strip Ciper Parker Hitt Advantage over cylinder cipher is ease of having many more alphabet strips French inventors Arthur Hermann and Georges Lugagne previously developed strip ciphers in 1893 and 1912 1912 Lugagne Strip Cipher M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

M-94 - A Plethora of Prototypes M-94 designed by Joseph Mauborgne, based on Hitt invention First 2 prototypes in early 1917 made of red fiber and hard rubber 2 were made of all brass on wooden base (top right) Later prototypes made of brass and Bakelite (middle and bottom right) M-94 production model first made in 1921 of aluminum William Friedman made M-94 with changeable paper strips – M-136 was never accepted M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

Last M-94 Prototype? M-94 prototype from the estate of Bill Lear, founder of Lear Jets Lear was radio operator and trainer in Navy in 1918-20 M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

M-94 Acceptance Mauborgne sent 25 messages to William F. Friedman at Riverbank Labs and Herbert O. Yardley at MI-8 on 4/23/18 for cryptanalysis Messages were not solved after 6 months, even with a hint Mauborgne had the M-94 adopted by the Army William F. Friedman Joseph O. Mauborgne M-94 was approved on 4/16/1921 by the Secretary of War Instructional manual published on Feb. 1922 Total of 9,432 devices were manufactured 8/9/1943 the M-94 was declared obsolete, replaced by M-209 M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

Mauborgne’s Challenge Messages 25 messages of 25 characters, all used same key Hint was given, one message contained “are you” Friedman expected military type messages, so never solved them Messages were revealed after Mauborgne’s retirement in 1941 Chlorine and oxygen have not b Cyanogen is a colorless gas in Xylonite and artificial ivor Llangollen is a town in Wales a Yvette are you going shopping Orthophosphoric is a compo Caoutchouc is closely allied Palladium possesses a power o Oxydation caused by it probab … M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

Models with Changeable Alphabets M-136 Cipher M-137 Cipher Late in 1933 the M-136 and M-137 were designed M-136, designed by William Friedman had changeable paper alphabets around the wheels, held in place with springs. Only one prototype was made and proved impractical to use M-137, complex flat strip cipher device with pulleys and springs, which proved to be unwieldy Simpler designed M-138 became the model adopted for changeable alphabets in 1934, from Hitt’s design 20 years earlier M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

How to Break the M-94 Number of wheels gives a cycle of repeating ciphers Selecting a row for encryption means all offsets are the same A letter cannot encipher into itself, like the Enigma, allowing cribs to attack After alphabet sequences are known, synoptic tables can aid in faster decryptions Germans used IBM equipment to break the M-94 after the US entered WW2 By April 1942, messages were routinely decrypted Signal Corps estimated the M-94 could be broken in 6 hours or up to 2-3 days M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

Cylinder and Strip Ciphers US Army M-94 Cipher Device US Army M-138-A Cipher Device Original invention by Thomas Jefferson still in use 150 years later Parker Hitt’s inventions of the cylinder and strip devices used for 4 decades - from 1922 to the 1960s 27,000 M-94s and M-138s were made, making them the most used cipher devices of their time M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception

Download this Presentation CipherHistory.com/m-94.ppt M-94 Cylinder Cipher: A Story of Innovation, Intrigue and Deception