This is a general report on the origin, development and status of the Hagelin "cryptographers"-a word used here to describe the physical machines used in encoding messages (rather than the people working on codes). It is an internal and "confidential" report, slender and to the point. Its sections include "Models Built at Express Demand of the French Authorities", "Evolution of Hand Cryptographer Type C-362", "Hagelin Cryptographer Models" (BC-38 and C-362), "Methods of Operation", "Superiority of Hagelin Cryptographers over Competing Makes", and others, including "How to Sell Cryptographers". Of particular interest to this post is the mention on page 14 of the "Enigma", which is really just a very lonely statement, limited to mentioning that the machine is not sold outside of Germany. Of course we well know that the Enigma (which is one of a family of related electro-mechanical rotor cipher machines) was being used very heavily inside of Germany--and France, and the Soviet Union, and several other countries, though it was in fact being used by the Nazi military. It just feels odd and uncomfortable to see this ordinary commercial mention of the machine whose working and transmission was known to the Allies, a knowledge that may well have been one of the great turning elements of the war. And there it is, on page 14, in a restrictive distribution announcement.
Notes
1. The Hagelin Cryptographers, an Analysis. Stamped CONFIDENTIAL; printed in New York: Ericsson Telephone, 1942. Mimeographed sheets, stapled. 11x8, 19pp. Offset, typed document. Stamped "Accessions Division, Nov 11, 1942, Library of Congress". With an accompanying cover letter with the rubber stamp of Ericsson Telephone, Sales Corp, NYC., and dated July 3, 1942.
"The basic principle of a Hagelin lug and pin machine is easy enough to describe. In the C-38, used by the U.S. Army as the M-209, six pinwheels, with 17, 19, 21, 23, 25, and 26 positions on them, can be set by the user with an arbitrary series of pins that are active. For every letter enciphered, all the pinwheels rotate one space. The combination of active and inactive pins is presented to a cage with 27 sliding bars. Each bar has two sliding lugs on it, which can be placed either in a position where it is inactive, or in a position corresponding to any of the pinwheels, so that it will slide the bar to the left, if the pin currently presented by that pinwheel is active. The number of lugs sticking out rotates the cipher alphabet against the plain text alphabet. The two alphabets used are just the regular alphabet, and the alphabet in reverse order, from Z back to A. This meant that encipherment was reciprocal, although the machine still had a switch to select encipherment or decipherment: this determined if the machine printed its output in five letter groups, or if it translated one letter, chosen by the user, to a space. The C-52, a postwar version of the Hagelin lug and pin machine, added an extra five sliding bars to the cage that, instead of moving the cipher alphabet, caused the stepping of the pinwheels to be irregular. The first pinwheel always moved, but the remaining five pinwheels only moved when their corresponding bars were slid to the left. The six pinwheels were labeled A, B, C, D, E, and F from left to right; bar 1 controlled pinwheel B, bar 2 pinwheel C, and so on. Also, on the C-52 the lugs could be moved from bar to bar, and the six pinwheels were chosen from a set with lengths 25, 26, 29, 31, 34, 37, 38, 41, 42, 43, 46, and 47. Using the pinwheels with lengths 34, 38, 42, 46, 25, and 26 allowed one to achieve compatibility with the C-36: provided one also turned off the irregular pinwheel stepping feature. The alphabet always started from its normal position, instead of the position last used, before being rotated by the projecting slide bars. This was perhaps the machine's main weakness, as it made attacks based on frequency counts of displacements possible, but it was perhaps unavoidable, since there was always a slight possibility of occasional mechanical errors. Particularly as the machines were often used on battlefields." -- Quadibloc blog, here (http://www.quadibloc.com/crypto/ro0202.htm)
Comments