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CL.ASS: 

sY~'TEM: 

llETHOD: 

NAME: 

REF ID:A273007 

Cipher Ma.chine (Electro-mechanical) 

Monogra~hic Substitution, Polyalphabetic (Related Sequences) 

Circuit Rotor Maze, Through Path, Gear Motion Control 

"Securitas• Cipher Machine 

DEVELOPMENT: 

Application for patent filed in Germany, 23 February 1918, by 

Gewerkschaft Securitas, of Berlin, one of the companies later associated 

With the development of the "Enigma". Inventor's name does not appear in 

the patent papers, but other evidence indicates that credit should be 

given to either Hugo A. Koch or Dr. Arthur Scherbius, or possibly both. 

It is not known whether this machine W8S ever manufactured commercially. The patent, however, is especially significant since it is the 

first one (with respect to filing date} in which the circuit rotor 

principle is used. 

PATENTS: 

GER. 416,219 (Gewerkscheft Securitas, 8 July 1925, Cl. 42n-14). 

The basic patent. 

GER. 416,833 (Gewerkschaft Securitas, 27 July 1925, Cl. 42n-14). 

Addition to GER. 416,219, providing for non-electric (e.~., 

pneumatic) rotors. 

DESCRIPTION: 

An electro-mechanical cipher machine in which the circuit paths 

between a keyboard end e. bank of incandescent lamps are irregularly 

penauted by means of an intermediate rotor maze. 

The chief embodiment of this invention is shown in a me.chine With 

a k:97board end lamp bank mounted on e. hinged plate above the rotor maze. 

The latter includes four circuit rotors between two endplates, the rotors 

being stepped irregularly between encipherments by a set of gap-toothed 

gears. Pressure on any k97 causes current to flow from positive battery 

through an encipher-decipher SWitch, via a conductor to one endplate, 

thence through the four rotors to the other endplate, back through the 

euoipher-decipher awitch to one of the indicating lamps, and from there 

to negative battery, thus completing the circuit. By means of the encipherdeoipher nitch current may be sent through the rotor maze in the opposite 

direction to pel'tllit decipherment. 

The rotors ere adTanced irregularly by means of a mechanical linkage 

conaiating of a main dr1Ting gear stepped forward one position each time 

a Jeer ta depressed and t0ur gap-toothed gears ot dttterent sizes, each ot 

Which control• the m<>T•ent ot one ot the rotors. 'l'he gap-toothed gears 

are mounted. on two separate shafts, two gears on each shatt, the latter 

being coupled b7 intel'llediate pinions to the main driving gear. Two 

setting knob• are proTided, by meana of which the shafts can be pulled 

out, allowing the geara to be disengaged and realigned; in addition, the 

tour }!\t~ rotors ae;y be arr~ in~ ~~---@! llOTed by hand 

to Ul7~•1red N\ttuc at ta bectnntng ot a particular ••Hege encryption. 

The apectnca:Uou aleo .. dion tbe :pNsibili "t7 of stepping the rotors 

u 1n a OOWlMr 80 that. tor ~le, Rotor 2 will adTance only afier a 

. @'pp roved for Release by NSA on 09-12-2013 pursuantto E .0. 1352a 

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REF ID:A273007 

com11lete revolution of Rotor l; Rotor .3 will step only after a complete 

revolution of Rotor .2; etc. In an f:'<dditional patent, the drawbacks· or 

electrical conductors are pointed out snd provision is made for carrying 

energy through the cipt.er maze by the u~e of weter, oil, comprefi&ed air 

and other means. 

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