ri-·-··-· 

i"" 

1 •· 

! ; . 

WAR DEPARVSNT 

OFFICE Of'. THE CHIEF SIGNAL .OFFICER 

WASHINGTON· 

Au.gust 210 1931 

i·.. There is. ~loeed ·a draft of the specifications and claims" 

appl,ical?le to t.~e cipher machine now· being developed at the laboratories. !here 1s also enclosed a dra'llting which accompames the· 

&pecifi~at~~s _and claiinf?. 

2a lfhe:se were arawn ap bJ Hr. Friedrmm: and represent · his 'ideas 

aith.regard to Q proper description.suitable for forming a basis for 

application tor a patent coverillg the maoh~Gh. :At 'he sewe time theee 

. should be reg$rded as tentative· ~nd.. this·. Division will appreciate &ny 

changes, comments or criticisms. deemed· a4v1.sable by. the laboratories. 

For these ·r•asons it is ·sugge..steid ~hat ·these enclo.eures· be forwarded 

:to the. laboratories YJithoa.t delay. · · 

2 Eneloeurosa . Specifications and claims, . . . 

· l Draw l11g • · · 

D. I!. Crawford, 

·t.'l&Jor, Signal: Corp~. 

\. : 

.. 

. . 

·peclassified and approved ·for release_ by NSAon ·11-20-2013 pursuant to EO. 1352§ ... :::;:•.-·· .. I ,.f_..':·· .. &.:,. ... SI,,...-, ••• 4.3-: ................. _A@ .!. .. £.; ... t.LJ.P .. :5, ..... . ::= ...... ~ ....... ·-· .. ;: ... : . ......... .,... ..: .• : ..•. : ••.•• · . · ..• : • .... x ·x. .. ·: ... . a: w .. (f· .... c:z.: __ .. ,.:::h~··;:?.(·~~:;;;; .: 
REF ID:A522174 

DRAFT 

The obJeot ot this inventio~ is to pro•ide a cryptograpb tor encipher-

,_ ing and deciphering messages automatically.1 rapidlJ, end· aecurel7. 

A further obJect or this 1!Jvent1on is the provision of a ceyptograph 

·controlled by a modified plural•unit•code tape transmitter through whic;h 

ia passed a key tape which &eTYea as the keying element in the e~cipherment 

or decipherment ct meesage.a. 

A further obJect ot this invention ie the provision ot a cryptograpi:., 

which, although empLoying tor its keying element a plural•U111t•.code of the 

. . 

Baudot t7pe (a code or 32 permutations), navertheleea produces aryptograma 

tbe characters of w.bich are restr;i.cted to the 26 letters or the ·alphabet. 

In this respect the cr1ptograph exclat1:es the uaual eix extra. Baudot chfiractere, the tra:asmission ot whic-h ·oc·casicna mch difticulty in ordinary tele• 

grapby by the Morse alphabet. The way in which these six extra characters 

are eliminated constitutes one of the unique and important features ot ou.r 

invention. 

•A furt~r obJec:t. of this invention ie to provide a cryptograph adu.pted 

to function either independently as a eelf'•cont.ained cryptographic unii11 or 

in conJunction with an independent typewriter having a standard typewriter 

keyboard. In the first case, the cryptograph makee no permanent rec-ord ot 

"h· 

the message, but merelr prodaces evanescent signals sucb as light aignal&J 

in the second case, the cryptograph bring• about the making ot a written. 
REF :i:D:A522174 

record of the message •. 

A further obJect ot 'this invention is the provision ot a c-ryptograph 

. . . 

functioning at the transmit.ting end or a communi~ation system as a means tor 

indirectly controlling a telegraph transtnitter keyboard·, ao that the intell1-

genc:e to be traus:nitted is automatically enc-iphered before transmission;· and 

similarly, at the receiving end, a corresponding cryptograpb tunc·tion-s as a 

me.ans for indirectly controlling an ordinary tjpewrite·r so that the intelli• 

gence received in cryptographic form is deciphered before being typed by the .. ' 

typewriter-. 

By way or an i-ntroductory sta1;-ement ·to our invention, it may be· eCid 

that in practically all the portable. me.chanical, electrical 11 or mechanico• 

.electrical -c·ryptographing dedce:e or systems heretotO-re devised, the cryptog·raphing and decryptographing or messages ie entirely cont.rolled by elemento 

..... ._ ---.. .. __ . 

all embodied within the mechtmism itse-lf; that ii, the basic, or invariable 

elements concerned in· the. cryptographic treatment, as well as the keying9 or 

variable elemental tor controlling the cryptographic t.reatment are integral 

parts or ttae device or apparatus. In contrad1st1-nct1oo to this situation, 

in.our invention, only the· basic, or invariable. elements concerned in the 

-eryptogrCi\.phic treatment are integral parts 0:f the mechanism, the keying, or 

variable elements being wholly independent ot the mechanism itself, and consist 

or an extraneous factor which when properly associated ·with the mechanism con-
REF ID:A522174 

. ...-...... 

trola the brlaic or invariable elemellis of the· mechanism in: crypt-ographing 

and dec·ryptogre.phiag mess·age:a~ 

ID the drawings aooompanying and forming a part or this ·applic-ati·on, 

Figur-e l is a schematic rep:resentation of the c ryptograph; Figure 2 is a side 

elevation view, and Figure 3 i~ a plan view of the cipher wheel which is one 

- ··~ 

ot· the important ele?nE;nta in the cryptographing mechanism. 

It is- believed that an explanation of the schematic representation of 

our invention will term the beat basis £or· its understanding, and therefore 

reference will be .mi.de. to Figure l.. In this tigure, .i represents the keybpar.d 

ot the cryptograph, the orrangeme:nt of the 26 ke·ys thereof being that Of the 

standard typs..,riter keyboard exoep·t that o~ly 26 keys correspondii.bg to the 

·as· .letters ot the alphabet are included.. Eoch ke:y or the ·teyboard opera·tes 

an electrioal contact, .as shown schematically for the "Q" and •r keys. In 

addition, our keyboard ie provided with a universal bar wbic·h is actuated. with 

each depression or any key. Keyboards or this type are well known in the art 

and require -no further d•s~Tiptioa. 

The cipher wheel is shown at 2 in Figure 1... It may be made of bakelite 

or similar materi.al, and senee .as a. commutator for carrying 52 brush•t.JM 

centac.ts arranged in two rings or sets ot 26 each, one set being placed· on 

the obverse face, 3, or the wheel 2, ~he· other set being similarly plaeed on. 

the ,.averse face, 5., of the wb.ee.l. The 26 contacts on ·each f'ace are arranged 

e-quidistantly trom one another in a circle around the pe.riphery or t~e face, 
REF ID:A522174 

_,,-.....,_ 

the oo~tacta· on thef bveree face being connected to tboae on· the reverse 

face by means ot f'lexibl~, insulated conduc~ors ~i~~ pass thr~ugb the 

interior of' the wheel, as shown ~chematically .in figure l ror two p.U,ra 

ot· contacts. The cipher whe~l ia f'ille·d upon the sbart ..,., which seeyes as 

an axis on which the wbeel may revolve. 'l'he contac·ts ot the obverse face, 

3, ot the c.ipber wheel press against ball-bearing type contacts arranged 

on the fixed plate 4; tbe contacts or the· reveree face, 5,_ ot th~ ~ipher 

wbeel press against ball•belll"iag type contacts arra~ged on the fixed plate 6. 

The. tised plates 4 and 6 _eac.h contain 26 oontacte arranged equidistantly in a 

circle. The cipher· wheel ntYolves between these tized plates 4 and ·s ao that 

eac·h cont.act on the obverse face, 3, of the cipbctr w~ael presen:ta itself -·in 

. -

tum to ea-ch contact on plate· ·4, end each ·contact o·n the reverse· f~e, 5, of . . . 

the cipher whee~ presents itsel.r in turn to each c~n1;act on plate 6, as the 

cipher whe~l revolves.. '?h4' contaqts ot plate 6 are respectively connected. 

by c_onductors to the contact·.s of the keyboard 1; the co~tacts _ot plate 4 are 

respec-U.vely connected by conductors to a bank or '2~ electrical element·& 'lllhic;b 

may be small lamps, relays, Qr solenoids, only two ot· which are shown at 10. 

·For the, sake of S"iraplicity ot explanation, it wil~ be assumed that the elec• 

trical elements in. this bank are lamps. All ebown in .Figure "11 when the ke_y 

11Q" is depressed, assuming tbe cipher wheel to be in the position indicated in 

the ·agure, a circuit is. establi-shed aa follows& From positive pole· or 

battery ll through -conductor 12, closed contact at the "Q" ke1, conductor· 

13, contact 14 on fixed plate 6, contact 15 on cipher wheel 
REF ID:A522174 

. .-,.. . .-. .•. 

' 

- 5 -

.2, .Ct>llduc tor 16, contact l'1 O-f Cipb9F vheel 2, C·ODtCCt 18 Of plate 41 ·OODGUC• 

t·or 19, th.rough lamp 20, conductor 21 to negative· ·ot battery 11. Lam.p 20 has 

a translucent glaas window \)efore it, on which a letter is paint~d, say tbe 

let.te·r '"5". ilonce-, depl"e·ssicn. of the key 0 Q" qn. the keyboard gives the cipher 

·resu~tant ~", under the conditions specified,. 

Suppose tbut the key "W" of the keyboard i·s dep:reoaed., instee:.d or nrr. 

By following the pa.tu s~t up tor the electrical c·a.rrent, it will be eeeu that. 

the "Q" lamp will be lighte-d, Thus, reciprocit·y is established between the 

keys on the keyboard and the lamps· so that i:fi for· ex.ampl-., Q • w, in enciphering, W • Q in deciphering... The same reciprocal· relationship can be established 

ihrougbout the· ~lphabet b)' conneatiiig th~ ·flexible condu.ctcra iu the interior 

o-t the cipher wheel il'.l an ·appropriate manner to paire.d conte.cts on the ob-..rae 

and reverse faces or ·the cipher •heel. 

It the cipher wheel were sta-t.ionary, the relationship. between the key 

depreeeed and the lamp illuminated, ·that is·, :ln the· equivalence· between plain!'" 

text ud cipher letters, would be· ti:zed ·for each wir.iDg or the interior of the 

cipher wheel• But the cipher wheel ia rotata.ble and hence this relatiouhip 

is subJ.ect to variation. As "thus· far described our cipher wheel io by no meaaa 

novel ·in the art,. similar wheels be-ing well known in other cryptographa. Oar 

~ipher wheel is, however, .novel ~D respec.t to ~ertaiu· teatura.s connected with 

tht. ·iaay iA which the re lations=bip between plain-text and cipher letters ta 
REF ID:A522174 ··~ 

...-..... ·-. 

varied and controlled, . and these features will ~ow be p;resented •. 

T~.rim. or· tire or_ our cipher wheel• 2, is previ6ed with 130 pi~e ar• 

ranged i.-i five superimp·oS.ed bands, each band consisting of 26 e-quidista!!tly- . . 

spaced pin$• These pins -can be.- eleyated_ int.o operative positions or lert. 

remaining in inoperative posit·io,ns in groups 9t fives transversely to the 

tire, in acc·ordance with. tbe: permutations of the ~unit or Baudo-t c-ode. 

To explain 'l~hat is meant. v:e may say th~t according to the Dsudot code, th& 

penmrliatiOtl or e.lemeats ro.r ·f.h~ letter A, for example, is repreeen.ted thua; 

l 2 3 4 s ~ f ___ -~ J'or o.ur purposes we will let the :f s-ign indieate that a pi,n ,is to 

. . 

be elevated into ita operat~ve position, the. ·• sj.p, tho:~ it is to be left in. 

~ts· i~ope-rative posH.ion. In Figure 2 there is shown a side elevation. view ot 

a eec.tion of the tire of: the cipher wheel.• with the -pin·s now being de·scribec! .• 

The pins indicated by .dotted lines in. the figure repreeeflt pins which have bee.n 

J,:e.ft depressed in their inoperative position·SJ the pine· indicated by whole. linee 

represe.nt pins which ha~ been e~evated into their -ope.rative position!I... The 

l 

pe~to.tians represented in Figure 2 corree-pond to the Baudot signals for the 

lette-rs Y, z. and A •. The o-rd,r or ·t.he lette·rs 11;1 'ngure. 2._ ).s.1 or cours~~- only. 

illustrative,. sinc-e all. the pins c-an be arranged· in -; ::operative or tnoperati'fe 0 

positions _to correspond witb any·_sequenctt ·of signal~ of the Bau.dot. co~., and. 

heriee this sequence may be varie,d at 'J)li.11. 

The ·!unction of the pins on th~ rim ot the oipher- 1t1hee·l is to control tho 
RE·F ID :A522174 

---

- '1 -

cipbe-r-whee l transmitter shown a"t! 2"2 in Figure 1, 'llbic.h consists essential.17 

of & ·set ot· 5 contact•le.vers moveable between paired left and Fight CODtll:\l°\.ft 

· Bo~ly, these contact-levers ore .held against t.he- left c-ontact, by the action 

ot re-spe·ctive retractil~ sprinp, t.ut when a pin. on the- .rim or th-Ei cipher wheel 

ie. in its o-pe.rative poo.ition 11nd ean therefore. prese·nt itself to the contact·-

lever with ~hich it is ~aociated, it presses _against the· contact-lever and 

c,ausee it. to make contact at the· right.. Pins in their inoperative position do 

not., .or course, act "Upon' the.se c·ontact·-levers, allowing the ·1atter to remain 

against their respective left-band contacte:o The· :function of the paired con• 

tacts controlled by the reepective -co~tact-.levere of the cipher-wheel transmitter will be explaiz:1ed pre.s·ently •. 

O~ the rim or the. cipher wheel,. and near tb& ed&e or the reverse tac~, ·51 

there is !l ratchet w.heel1 shown in Figure 3~ "Ihis ratchet. whe-ol contu~ 26 

equidistantly-spaced ~e-eth, only fiYe of which are shown in Figure 31 one tooth 

beii.ag J.abeled. 23. It is likewise labeled 23 in Figure.·. 1 .. , msociated with ·the 

ratchet wheel is the. pawl shown at 24, P'igures l and 3 •. · The ratchet 11b:ee.l ·and 

pawl, t-cgether ';'ith solenoid .25 and its armature 419. Figu.re.a 1 and 3, control 

the movement or the cipher wheel in its rotation about the axis, 7, under the· 

drive of c.oiled s·priag 81 -which is. wound by .a motor not shown in the drawt.ag,-

The inovet:i.ent of the- cipher wheel is step-by~step, at intervals which will ce· 

explai·r.ed au.bee quent ly in disc·uesing t·he way ~n "lfbich the whole system f'Qnc--
REF .I.D._:A522174 

T.he ke.7•tape transmitter·, 26:, Figure 1, is a slightly modified Bauciot 

code tr.anamitter mob ae is employed with printing telegrapb equipment of 

the 'He.ster.n &lectrie or Uorkrum type. Its g.eneral .features med not be ex~ 

plained,. -1milar tnmsmitt.ers being well .known in tha art. It is salric-ient· 

ta'te. 

to say bere tbat a"contaiDing perforations permuted in accordan·ce •ith the 

Baudot C'ode is passed through tbi& traoem-.itter, sett.ing up a series of S cG·~ 

·tact.s inside the tranemitte.r in accordance ·wi.tb the Baadot Code.- The tr-~tte·r 

ia, .o·t c·ourse·, also provided with a t-ape•.etepping Dle.guet, 2"1., the t'unetion. o'f 

which i-s to step the tape tonra.r(j eat proper ·intervals. 'fb.e principa.1 dif"f'erence b•tween the transmitter as l)e·ed in standard printing t .. elegraph e.qu:i,pment 

and as- used 111 _our invention consists· ;ln· the my in. which the left and tight 

paired contacts of -tn~· normal ·Baactot tupe ·transmitter are interaonnec-te·d.~- ·ID 

the normally-wired traf;.smitter the five contact.•levera .and U;.eir tali associated, 

paired c-ontacts are members of a .s-et ot fiv.e separate or· independe.at · circuits; 

1D. the trans:r.itter as· modified for "our purposes t.ne ·five· ccntact•levers and 

tbeir ten associated paired contaets are members· or a si~gle eircuit,aa; - explained in the ne.x:t paragraph. 

. . 

Tbe. key-tape transmitter, 2.6, is associat.ed ~z1d. tanctions- Jointly with 

. a"',tu \ .... v 

the cipher-wheel transmitter, 22, to control the"displaeement.1;1 of the cipher· 

wbeel in the £allowing ma.nner. Rote relat 28, which is energized by currerr~ 

tram battery 299 through a path which begins at conductor 30 and inalndea only 
- REF ID :A522174 

ten. ot the twenty contaots Uld ·all the. c:ontact-levers of cipher-wheel tnm&-·. 

aittor,. 22, and key-tape trmismit-t.er, 26., md. emerges along c.onductor 31. Hote 

al.ao the illnst.rativo set-up or .c.ontuc.te and corrt .. act..-.leverD at 22 ·and 26 11). 

Figu:re l, in which a specific css:e is p1-e$ented. It is assumed there. that the 

arrangeaent of operative. pins on the cipher wheel w-hi"ch are Ut that moment present• 

ing themselves to ·the contact ... levors of the· ciphel""!'-wheel transmitte·r, ·2"2, cor"."" 

responds t,o the Baudot germi.1tation for letter "Z''• At the same mo..."'llent ·the char-

-act.er on the key tape ·and the permutation of con·tacts set-up within -~he key-itape ·tranemitter, 26, als-o cor.responda to the· 1e·tter "Z". Note· that in view 

-of the :manner in which the twenty contacts and the· ti;n contar~t-levers of 22 

and 26 -are j.nterconnec·ted, the circait fr.o:n battery -29 through rel·ay .28. is complete.d only when the ,.whole •• s-e\ o·.r elec.trical. conn~o.'t,iona estat>lishe-d at. the· 

key•tape transmitter, 26, c:o-incides with the whole .set of conneciions esta.blisbed at the eiphtu•-wh-eel transmitter, 22.... Hence, if "Z" is ae·t up in keytape t:ransm:i tter, 26, relay 28 will operate only 111hen "Z.. is set up !n the 

is set u..p 

cipher-wheel ·transmitter, 22. Similarly if any other. l4atter, say ~x",/in 

the key-tape transmitter, 26, _relay 28 will operate ·only when "Xn is set up 

in the. eipher•wheel transmitter, 22.. 'llle c·omplete paiJii. or .the current when 

such ccincidence of connections in· tr~emitters 22 -end 26 :is ee-t.sblished is 

as· follOl!iS"I 

From positive of bat~ery 29 ~long conductor 301 through all the contac~· 

. - ... &. p 
-· 10 -

levers and the ten assoc-ia.te!i closed contacts of transmi:t;ters 26 and 22, con• 

duotor 31 to back contact 32-, ot armature 33, winding ot relay 26, conductor 

34.1 to negative or battery 29.. lt is, obvious th;at _since. the armature 3.3 and 

back contact 32 ot' relay 28 form parts of the· circuit for energising r&by 28.,. 

as. s·oon as the relu.y has re.o·eivvd an impu_ls& and armature 33 is att·racted, the 

ci~r.dt i'or energi..:ing ·relay 28 is broken at c.cnte.ct 32. Sir.i.ce arcature 33 1.s 

'U,nder ten·sion of a retrac.tile spring., ii' not prevented from being pulled 'baek 

·intG its normal position on releilSe or reh:.y 28t armature 33 woul·d reeetablieb 

contact at 32 and oould set up a chattering. But the mechanical arrangements 

·are such that when. armature 33 ·is first dr•n up by relay 28 it paase.s by and 

is immediately en~eged by lever 35 and· held from returning to its retracted 

position where it can rees·tablioh contact at 32, until lever 35 is displaced 

by mechanical; action· to be desc·ribed later. Armature 33 or relay 28. also controla 'the solenoid 25, already referred to, which,. i:n turn. controls l:be rota• 

tion -of the. cipher wbe-el1 2,. in tile following maiinei-: 

The moto·r-op&rtLted. coiled spring, a.,. tends to rotate the eipher 11heel 

in the. direction indicated by the s.r:·ot;, f?ay to the right.. Tilis rotation is 

step-by-step, controlled by the solenoid 251 and the r atcbet r6i'erred to. above-. 

Assume ·t.he contact-levers in transmitters 22 and 26- aet up to different pei·m..: 

tationa eo that relay 28 ie not ene~gized a~d hence contact 36 is clo.aed.· A· 

current .·starts from positive of battery 347 thro~gb conductor 38t closed contac·t 
REF .. I-D :A522174 

..-. 

•. ll ... 

36., coaduet.or 39, hack cont.a.ct 4.0, e:l'!Dlil.·~ttre 41, conduct.or ·42, •indi11g .or. 

e.o.le·noid, 25," conductor 43, te negtii.tive of b~ttery 3'1. A momentary impulse. 

passes- thr·ough 25 i.;,.nd c&.usee anne.tu,re 41 to· be attracted,. breaking the cir• 

cuit ~t back contact 4.0t whereupon armattlre 4:1,. u~er acti~n or its ap.riag, 

.returns and Qgain c·loses t·he· cirauit at 40. Howev-eze.,. the mecl.1a.nical. arriillg6-

m~-nt +s. fr'UCh that the m9mentary· att.rac t.ion or a.rmatare ~l releases t.he pal,. 

24, associate.d with the r6tchet on the- cipher wheel and thus allews the ciphGT · 

wheal, driven by coiled spring, a, t.o oovan~e o·ne step. Thus, the cipher ··.vheel 

cont.inue$ to move, one- -step at ~ time, so long as back contact 36 of relay 28 

remaino closed. ~hen, however, the permutation of contaqts set up in tr.e: cipherwheel transmitter becomes the s::me as that s.et u.p in the key-tape ·transmitter, · 

thus causing the completion. ·of .tbe circuit through re.lay 28 ae already described, 

and ·thus, when e-on·t;act 36 is opene.d~ under the ac·Uon of' relay 28, and is held 

open by levei· 35 as de-scribed .above, sslencid 2S c.a.nnot. opera.te ·to withdraw arm.ature 4-l; hence the· pawl 24 cannot ·be rel.ea.s~d, 1:1hcr01.1.po_n th6 cipher wheel cannot. 

advance-any further. >.a stuted before, the first impule~ throagh relay 28 caaaee 

armature ·.33 tG be att-ract~d, to pass by lever 351 •hi.ch then· engages tbe araature. 

'l'hua contact 36· remains open as long ·u lever 35 engages., ~Alla holds it.. It iai 

only within this period, whe-n the eipher vJheel is· st~ti~naty,. that the keyboard, 

~ · .•

' 

l, can be manipulated• the me.ch~nical arrangement ·being supb that the keys or the 

' ~ ~ . 

keyboard. rare .locke-d e.z-ce.pt when tile· cipher w~el is· o-tatio~ry. · 
REF ID:A522174 

- ............ 

.... 12 -

Sappose .rJoe a key ie de-p"s·sed. The cipher resultant will .be ·det~.rmined by 

the positio~ of the ciphe·r U>heel at this time, becau.se the circuit e.stabliiahed 

through_the cipher wheel depende upon ·the exact rslative positiQn of this whe.el 

wi-tli respect to fixed ~lat.es 4 and G. When a key i~ ~pressed, the cipher reattl• 

tant is shown by the illuminated ltll!lp; the latter continues to be illuminated oo 

long as the key is held do-:m .• 

..4fo 

We .return now to relay 28 and its other arm:J.ture ~. Tha h ttsr controls 

the opera:tion or the tape-ste-pping magne·t; ·27 of the k~y-tape tranS1Ui~.ter 26, in 

the following· manner·l. 

The tape~stepping megn&t. 27 i5 s.etunted by battery ·441. but the· eire·u.it ie 

~~"'~~-~ normally open e.t i::ontact 45. \'Jbe.n relay 28 is energi.zed, hqwever,i\ contact 4~ is 

moment.arily closed,. allowic& tbpe-stepping magnet '//I to fu~tion,... This c.auee• 

the key tape ·.to o·tep forward to tt;ie n.ext position. It ~ill remain in tllu.t posi• 

tion. until the next time relay 2S is entrrgized" 

There now remains to be deocribed only how le~er 35 is controlled. 

The keyboard ia provideq· with a uni"Versal bar.,. oper.r:i.bl~ by ev.er; te7. 

Whell a. key is depressed ond then relee.sedt the universtU bar1 near the close 

ot i·ts upward swing en return to normal positio.n,. ac·tue:te.e the lEver _3S, and 

causes it to be w.ithd.z·a.wn· rrom its engngem.ent w:i;t.h !n"muture 36.. The latter 

immediately retums to its· normal, retra.cted p·ositioc, allowing ·contsct.s to 

· be reestablished at 32 and 36.. In the me·antin;e ·the ta.pe~flep~ing magnet 

- ••• , ... f"' • ·- --.· • - ·--· - • • • 

-~ 

. ,_ 

' 
RE:f __ I;O. ;_A52.2174 -···- ·-- ·--------· ·-·-~-

.-· 

- 13 -

haring been actuated .as descrj,.bed above, one or two things can ~pen aa 

regards the E!•"t-up -ot connections μ. kertape transmitter 261 either ·a new 

set or connections. 'between contact-levers and paired contacts has been eetablishedt 01"., by cbanee, if two similar characters occu.r in sequence on the t·ape, 

t·be eame set of oonnectiona as before hu ~sen establiahed. These two cases 

are described in tLlrnt 

(1) If a new ·set. of connectione in key-·tape transmitter 26 has been eatab-· 

lished, ea1 a set corresponding to the Baudot eignal tor 1tx•t, the set of conuectioas no longer matches tbat set up in. the cipher-wheel t·raasmitter, 221 

which, as we have seen, corresponded in the preceding case to the letter ftz~. 

: , Co!Uile(luently, immediatelJ upon cloeing ~;f contact at 36 under action of the 

universal bar, the circuit. for energiaing aolenoi.d 25 is closed, allowing tbe 

: ;, 

Cipher wheel t-O step forward. It will CODtine to ·dO 80 until that. set•Up Of 

pim on the rim ot ·the cipher wheel corresponding to letter 11·xtt presents itaelt 

to the c.ontact•lev·ere of t-he cipher-wheel transmitter,. 22, whereupon relrq 28 

ia energized, contact at 36 is broken, solenoid 25 deenergized, 13Pd the cyole 

bas been e·ompleted. 

(2} Ir, by c.hance, the ne-xt character on the key tape is the same as 

betore ("Z" again). relay 28 is immediately eoergiaee, aince the cipber•wheel 

. . t-ra.n•mitter is still set .up tor pel'11111tation ""Z"•· Solenoid 25 does not ge.t ·a 

chance to ~ction and the cipher wheel is held in place·. 'l'wo letters are· 
REF---ID-:-A522174 

- l4 -

therefore enciphe.-ed at the same position or the cipher wheel.· or course, 

it the- key tape now .consiet• ot a ·series of ••z 's", the ciphe-r wheel will rer:iaia 

in fixed position during the encipberment of a -corresponding muaber ot letters. 

It is obyioue that the permutations of perforations on the key tape a& 

/ 

well as the permutations or operative pias on the rim or the Qipher-wheel must 

be .reatrict!'d 'to· two sete or 26 "similar permutations, otbe.n1iae there wou.ld be 

times when the cipher wheel would continue to l"H'Olve indetinitely and 110 en-

.cip·herment or decipherment could take -place. This is true tor the res.son that 

in order to bring the cipher wheel to rest it is easent.ial that a pe~tation 

ot pins on its rim exactlJ coincide witb that permutation whioh happens to be 

set ap at the key-tape. trans.mitter at that. moment. This restriction t-o two 

sets ot similar permutations does not, how~ver, reduce the oryptograp~c seeority 

of the system. in an7 de~ree whatsoever. 

In addition, attention is especially called to the my in which a serioo.a 

. . 

disadvantage of other cryptographa empl.oying the Baudot code for cryptographic 

purposea. is obviated in our system. In order to explain what is meant it is 

necessary to enter into a briet discaesion of Baudot transmission. from the 

pr~ctical, economic point of view. For this purpoee we can hardly improve 

upon the excellent discussion to be found in u. s. patent Ro. 11 416,765, 

issued Ua1 23, 1922, to G. s. Vernam, which is as follows; 

"Arrangements have been developed for enciphering uad deciphe~ng 

code messages by the use of printing telegrapb equipment, in wnioh ar ... 
REF ID:A522174 

- 15 -

_rangeme~te .the charac~ei·a of a mseage, whe-n in code formation, a.re combi~d ln efte~t with the code coabinatioaa of one or more perforated 

key tapes and thtt reaultiog code combinations make up ·the characters of the 

enciphered meseGge• §fl!},qfJffHf;}f!·.¥1J. In t~is devic• the code c·ombinationa _ot 

the enciphered or deciphered message a.re recorded on a -p.errorated tape or 

the corresponding characters may b~ print·ed if desired and the message 

may then be. tra\'llmittsd in a~y desired manner to its destination. 

"One or the well•k.noq codes utilised viith messages prepared by 

printing·telegraph equipment is the Baudot code in •hioh each character 

is represented by a combination or five 'marking• or •spacing• impulses. 

In a five-unit code of tbis sort there are thirty-two different code combinations of which twenty~eu are used to designate letters of the alpha'"' 

bet and the remaining aix aombinations are uoed as 'e-tunt • filignuls to con• 

trol operatione ot the printiog mecbailiam, such as 'liae feed,' 'carr.11.lge . retum,' etc. In the above-mentioned met.bod of e~ci.phering meesQgea theee 

ob "stunt.• signals will ordinarily appear at irregular intervals 1a the 

cipher message and therefore they· mat be recorded 1-n some •Y in the . 

Wl"itten or printed form or tbe -~sage. The presence ot these •stunt.• 

signals can not be avo1ddd by omitting them from the original message 

and key tapes becuase ot tbe r act that they· are· produced by various c.om• 

biaa~io.ns of letters in t~e message. with letters in the key tapea. If 

aD· ordinary printer is used to record the cipher message the result would 

be a badly confused message due to the rw:t that the 'etunt' signals occur 

e.t other than the ·prop~r times. To avoid confmJion of t-his sort printed 

characters must be used to represent the •stunt' -signals in the printed 

tora of the message. It might also hi possible t.o utilize numerals or 

punctuation marks tor this purpose •. A cipher message prepared in the 

above manner is not in desirable form for transmission oYer tbe ·ordinaz"J 

commercial types or telegraph or cable lines for the ·following rea&0na. 

·The usual pre.ctice in preparing c.ipher mesaagea tor t.ranamiseion over 

commero.ial llne:a is to divide tbe letters into groups ot tive. Tbe telegraph coapaniea count each group of five l•tters as one worl .in charging· 

tor such messages.. 11.Ued g~~ps containing ~oth letters and nQ!ler.ala ~· 

not accepted tor transmission by cable and when transmitted oyer land lines 

each such group i.s counted ao five words. Jlg the BUID8r&la designating 

'stunt' signals might .appear frequently in the cipher mess.age it will be 

seen that the charge fbr traqmitting such a message· over· a cornerc.ial 

line would be exceedingly high.q 

In the patent to which reference baa Just been made., a specitll me.cbt11nism· 

was deYieed·to suppress the six extra charaatera which cause all these diff'icul• 

tie•; end while accompliebing. the obJeot inte-ndedJ tbe me-cbaniam is- quite eom• 

plicate•·and has in addition the turther disadvantage that th• method selected 

to. accomplish the suppression of the six extra cbarac.tera ·results in increasing 

the mmber of characters to be tranami tte.d by as 1111o·h aa 10 to 30. per ce.nt. ID 

our inve·ntion~ ·both these disadvantages have been eliminated in the simplest 
REF ID:A522174 

·.·· -

- 16 ·-

.111111ner pos.sible, via., by arrangements 11hicb nec.ea.sitate. only 26 ot the 32 

Baudot permutations for· ctcyptographic purposea. So tar as eryptographtc 

tecbniqtut is ooncerned, basif:ally our arrangements for eliminating t.he au 

extra charact.era ordinarily introduced b;y the use or the· ·Baudot oode for 

cryptographic purposes ditter trom those ~eecribed in·_ the patent referred 

to above in tho following re~pect. tu the cryptographic syat~m underlying 

the la,tter me·t.hod tha cipher ·resultants in the cryptographic proces~ are ~he 

resultants· of electrical interaction between a.set of signaling elements in 

. . 

the Baudot code .set up by a message characte.r and a set of signaling element~ 

in the same code se·t up· by a key cbaracte·r; these resultants oau not be restricted 

to but 26 ot the 32 J:'O&sible Baudot 'pel"llRltations because of this biteradtion. 

In our Cl"J'~ographic system the cip·her resultants in the. cryptographic process 

are not at,all the resultants at electrical interaction between two· sets of 

signaling eleme.nts in tbe Baudot code; the signaling ele!Dent representing the 

message ohamcte~ ia not at all in the B.audot code amd does not interact directl.1· 

wi'th the signaling elements re·presenting the· key character, nor 1s the ciplae:r 

re.sultant represented by signaling elements in the Dau.dot code. The role· the 

Baudot code plays in our system ia·, s.o tar as· signaling elements are concerned, 

only ~~ indirect one, and that is why in our system the restriction ot cipher 

characters to a set or only 26 ie rendered easy, without an7 apparatus apecit.i.-

cally introduced to suppress the six extra characters. 
.-

'!" l.'7 -

lt is obvious t~t instead .of having the c.-1ptograpb !unction to prQduoe· 

. . 

·eYane~ent signals of th"& t;pe indicat-ed ill· the foregoing deacriptiOft1 it iO. . . . 

poaa~ble· to provide at 10,_. ft.g111"8 1.1 a set ot 2~ solenoids,. instead -of a ·aet 

ot 26 lampe, which r;olenoida would ~t dire·ct.ly upon the keyboard or .a type,.. 

so 

writer with wh.ic-h they are ass.ociat.ed,/ae t.o cease the typewriter to print 

the letters ot the -cipher message-, in the c.ase of enciphering, and the l~t"" 

ters .of the plain-text message,. in t.he ·.case or deci.phering. 

;.Sain, tb&se soleQoids1 instead ot being associat.ed witb the .keyboard 

ot an ordinary typewriter, might. be associuted with the keyboard of an automa.tic telegraph transmitter keyboard, and thus, in f.he case .of encipheriisg, 

bring about the traDSmiasion or ~ignals co.rre,ponding to enciphered letters. 

At the receiving end at. "this ay'-:tfm., th~ receiye-d signals would aot direc.tly 

upon the· keyboard ot the cryptogfaph,_ and the letter would cause th.e recei!ed 

cryptographed signals to be dacip~red &nd, it ~he cryptograph at the recei.,_ 

ing end is asaoc~ated with a ~ypewriter as described in the preoeding ~ara• 

graph, the cr;vptograph would cause- ·9. written rec-ord to be made. of the deciphered message. 

lt is also obviaus .. t.hat the mechanism which we have provided permits 

Qf va,.~iationa i_n c.ryptographic result.ants other than th.oae introduced b~ 

chaogirlg the ke1 tape. One of the~e sou~ea ot Yo.riations lies in the 

p~ssibility or a.hanging the permutations or operative and inoperative pi'DB 
REF ID:A522174 

- .:·· ·:. 

·:.· 

- 18 -

OD the rim or the cipher wbee·l. Anotber source lies. in the changing ot 

connections between the ke1board contelets and the contacts of plate s, Figure 

. . 

l; or between the contacts of plate 4 and the signaling elements in b&nk lO. 

Another source lies in the changing ot connections between the cont.acts on ·the. 

obverse and reverse taces of the ci?her wheel. ·Finally, an importan~ so.urce 

ot Tariation lies in the changing of. the conaectiona between the pai.red contacts 

·· or the tape transmitter, 261 and the cipher-wheel transmitter, 22. All these 

sources of variation. e:aiating within the mechani-am itself· are subsidiary, how· 

e:ver, tc the principt;Ll source inherent i11 constant change of key tapes, and 

it may be said that so long as a given key tape coextensive in number ot ehar- · 

o.cters with that or the _in.telligence· to le enciphe.red, eo that no t,ro mesa.ages 

. . are ever enciphered by the same key tape. or portion thereof, and eo long as. 

thes.e key tapes consist of unintelligible, entirely randomized sequeuces of 

characters, the iDea,ages enciphered.accordicg to such a system are absolutely 

indecipherable without actual poeaeasion ot tbe key ~apes employed in their 

eucipherment or a.knowledge ot the sequence of the. characters on such· key 

tapes. 

W,.. -.lea•·-', 
REF ID:A522174 

-

1. In a cryptograpb, a 26-·element keyboard comprising a set. or 26 

contacts f'or closing respective circuits to a set or 26 signaling· eie'1ents 1 

-~~o..~-~-~ 

a rotatable cipher wheel,/or varying the connections between the. contac:ts 

or the keyboard and the ··e l.ements or the set of signaling elements, a first 

transmitter mech1U1ically controlled by the cipher wheel, a second tro.ns:nit.ter 

controlled by a tape bearing perforatic.ns permuted in accordance \?ith a pluralunit code, and meuns, under the joint control of both !irst ~nd second transmitters,,ror controlling the angular displacements of the cipher wheel • 

. 2. In a cr;yptograph, an electrical circuit comprising a source of current, a relay, ·a first aet of five vibratir1g coctact levers capable- or being 

permuttttively positioned wit_h reopect to t.heir ten associated paired cotltact 

points, _ttnd a second and similar set· of ccntuct leverti emd ccr1ta.ct points, the 

individual contact levers and contact points of both sets being interconnected 

in such a manner that ~he circ~it is compl~ted and the r~lay energized at only 

\1.~S.J;r: ... 

such times ~s the~series_ of connections established within the first· set of 

contact lever·s ..and their associated contact points is identical ·with 

aeries of connections established within the second set of cont!:ic-t levers 

and their associated contact points. 

3. Ia a cryptograph, an electrical circait comprising a sour.ce or 

current, & relay, a first set of five vibrating contact lev~rs capable of 

being permutatively positioned ~ith respect to their ten aasoci~ted paired 

contact points, a second and similar set of contact levers end contact points, 

- .. wwwwww •• 
REF ID: A522-l7 4 

-· --· 

the individual contac.t levers and contact points ot both sets being i~terconnected in such a manner that the circuit is completed and the reluy ener• 

~ '·. lJi',p.f.':'·,,:..r. .. 

gize-d_ at ~nly such times as the".series ot conr.ections es·tablished within -the 

first set of contact levers and their associated contact points is identical. 

with the/\eeries -~ of connect_ions established within the second set of contact 

levers and their bS&Ociated contact points, and means for permutativel~ vary~ 

ing as a set each of the twc said sets of contact levers·~ 

·4·. In a cryptograph, an electrical circuit comprising a source or current, a relay, a first set of five vibrating cont~ct levers ·capable of being 

permutatively positioned with respect to their ten associntsd paired contact 

points,-_a second and. similar set of contact leve-rs and cont&.ct points, the· 

individual contact levers· and c·onta.ct points of bo·u1 sets being interconnected 

in such a manner that ::be circuit· iS completed and the !'eltty energized at only 

I::!.: .. ;":: ... ~&ft,,~::f\,... ...... 

such times as the.fl< series of c·onnectioris established within· the first set of 

. ~~~ contact levers rand their ·ussociat~d c-ontact poi!1ts is identical witb the :Series 

of connectiona established within the second set of contac't levers a.ad theii-

~ssociated contact points, and means tor permutativ~l~ var.ying as a set each 

of the two said sets of contact levers, said permut~tive vari~tions being in 

accordance with- the same plural-unit code for both .sets· of contact lever·s. 

·5. In a cryptograph; an electric.al circuit c.ompriei_ng a suurce of current, a relay, a first set of five V'i.brat·ing contact· ieve:rs capable ot being 

20-
REF ID:A522174 

·-

permu~atively positioned with respect to their ten ·associated paired contact 

points, a second.and similar set of contact levers·and contact. points, the 

individual contact levers and contact points of botb sets being. interconnected 

in su.ch a m1::1nner th&t the circ·uit is completed and the relay er:1ergized at only 

'I .~. 

-..J."i..N:.·tt..--. 

such times as ·t.hei\ series or connec~ions established within the first set of 

'._}:;;,~. ;:~·,;' .. contact levers and their aQsocia.ted contuct points is identicul with the ~e~ies 

of connections estab.lished within the second set or conttict .levers and their 

asa~ciat~d contact points, means for penmitative~y varying as a set each or 

• 

the two· sets or contact levers, the. permutative variations for one ot said sets 

of contact levers being in accordance with one plural-unit code, those for'the 

other of the two sete or contac.t levers being in acc'ordance with a different 

plural-unit code. 

6. .In a cryptograph~ a cipher wheel bearing on its rim 26 .sets or pin.a, 

the sets being equidistantly spaced around the rim, each set consisting ot 

five pins. equidistantly epuc;ed tr~nsversely to the rim, each pin being c~pable 

or beinz fixed in an operative or inoperative position, the five pins of each 

eet being arranged in operative and inoperative positions according to a. different permutation of. a 5-unit code'! · 

'I. In a cryptograph, a 

~ 

rota~ab'e 

o..o 

cipher 

~ ~-

wheel"bearing 

~a--tr.,:Y on ite rim 26 ~ 

sets. 

of pine, the sets being· equidistantly spaced around the rim, each set consist• 

ing of five pine equidistantly .spaced tranevereely to the rim, each pin being 

·.:U 
REF ·-·ID :·AS2·2174 

'·. 

capable of being_· fixed in an operative and inoperative position, the five 

. ":-· 

pins of each eet being arranged in operative end i~operutive poaiti6ns according to a different permutation of a 5-unit code, the cipher 111heel ~leo bearing 

on its obverse and reve·rse .rucee respectively a eet ot 26 equidist~ntly apiaced 

contact surfaces arranged in n ring on the p~ripbery of said faces, the contact 

surfaces on the obverse face. being ·connected respec-tively to the contact aur~ 

. . 

faces on the reverse face, the c·onneetion~ being .r·crtuitous.ly e~tablished. 

~-O_Q.. ~--~-~-

8. In a crypt·ogrtl.ph, a rotatable cipher whcel~earing. o~ its rim 2\ 

sets of pine, the sets of pins being equidistantly spaced around the r.μn, 

each ee.t consisting of five pins equidistantly spaced t.:ru ·nsverse l;y to . th& rilll:t. 

e·ach pin being capable of being fixed in an operative ana inoperative poeition9 

the five pins of each set being arranged in operutive and inoperative positions 

according to a d_ifferent permu.tts.tion ·or e. 5•unit code., the ciphe·r wtieel ·also 

bearing on its obverse and reverse i'Glces respectiv.ely a set ot 26 equidistantly 

spaced contact surfaces arranged in a ring ·on the periphery of said faces, the 

• 

c.ontact surfaces on the ob'17erae race being connected respect1vely ·to t.he contact surf'ac-es on the reverse race, the connections being fortuitously established reciprocally in pairs. 

9. In a cryptograph, a relay ~n ~n electric circuit, a rotated.:>1~ 

cipher wruiel bearing on its rim 26 sets of pins 11 ·the sets of pins being 

equidi.stant·ly spaced around the riio, each se·t consisting of t~ive pins 

-2'1.-
REF ID : A52-2-l 7 4 -

.r--. :r"\ 

.., - .-

equid~stantly space.d ··transversely to the rim,. ~ach pin being capable of being 

.fbed in an operative .and _inopera.t_ive position, the fivs pffeils .of each eet be• 

ing arranged in op.erativ.e and inoper~ti".e pos.itione &ecording to a differe-nt. 

permutation of a 5-unit code; a ciphe·r .. wheel transmitter cont!'.'olled by said 

.i 

, 

' 

pins, said cipher-wheel transmitter qomprising a .set of te.n contact points arrange.d in tv10 groups of fhe· in opposite ~anks b·etween which vibrate fiv-e per•. 

mututively operable contact ~ever._a tangentially adjacent to the c.ipher-whee.l, · :l 

said co-ntact levers under control or the pins on the rim of the cipher!'!'~hee·l 

setting up a series ot five. portions of an electric current through all ·Of the 

contact .levers and tive of their ·ten associated .~oDttlCt points • .• -

.10. ·1n a cryptograph, il rel.&y in an elec·tric circuit, a rotut~ble cipher· 

\\iheel bearing on its rim 26 s~ts or pins, the ~ets or pins being .. "equidist~ntly 

. spaced ~round the rim, each set consisting of' five pins equidistttntly spaced 

. . 

transversely to the rim1 each pin be~ng .c~able of be-ing· fixed in an· operutive 

and inop£rative position, tt~e= five pins of each ~et- being arranged in ~perative 

and inoperative positions according t;o a different permutation. or ~ .. _5-unit code., 

a ciphe.r-wheel transmitter controlled by said pins, said cipher-wheel trnnemitter comprising a. fir.st -se-t of te~ c·ontact points arre.nged in two groups ot 

ti.ve in opposite banks between w.hich vibrate five pemutativ.ely operable ~on• 

tact levers tangentially adjacent tei. ihe cipher-wheel,, said cont.ac-t levers under 

control or the pins on the rim. Gt the cipher-wheel eetting up a first series 

or five portions of the. circuit. for operat.i·ng the relay, said portions 

.. ..:i&·-

............ 
REF ID: A522-1 i'-4 

_:... . .:-

including all of the contact levers .and five of their ten associated points, . 

a perforated-tape trans:nitter controlling a second aet ot ten c·ontact points 

arrange_d i·n· two. groups of five in opposite banks -betwe-e.n which vibrat~ five 

permutatively operable contac.t levers thus setting up a second series of fiv.e 

portions· o·f the s·ame· circ.uit tor operating the relay, said portions includ-

_ing all or said cont.act levers :and· five of their ten associated contact- points~ 

tb.e ·various eleme~ts of .said .first and second eerie.a or portions ot the circuit for operating the- relay being interconnected in such a manner as· to form 

a co~tinuous path for the passage d~ the current only under certain specified 

condi~ions. as regards the per:mJtat.ive posit"ions of the fir·s·t and second sets 

· of perm~t.atively operable· contact l~vers • 

. ~· 
REF ID :AS.22174 

-~. . .. 

11. In a crypt·ograph, the coni~ination or a cipher-wheel transmitter, 

a rotatable cipher wheel bearing on its rim 26 sets of pins capable ot 

-~ 

being arra.r.iged,. as ·regFdB their being 1.n .operat.ive·. and i~perati ve positions on the· rim1

permutatively in groups of· f'1ve in accordance ·with 26 ot 

the 32 permu.t~tione or a 5-unit code to <X>nt~l the ci'pher ... wheel transmi~ter, and a tap.a transmitte~. 

12"! In· .a c~;y~agraph~ the combination of. a ·cipher-wheei transmitter, 

a *'otatab le ·cipher whE!el bearing on its rim 26 sets· .of pin~ capable ot 1Je~ . . . . . . . . 

. . . . 

1ng arranged,ae r~garde their. being in operative and ·inoperative positions 

on the rim; permu.tati,veiY in gro~s of five in •ccordance with ·26 or the 32 

t· pe·rmutations ... o.f a 5-uni~ ~ode to' control the cipher-wheel transmitter, and. 

I' 

a 'tape transmitter, said tape transr.litter; under.the control of a .Perforated, 

k01' tape which is pa.seed through the t.ransmitter~ and said ciphe~•heel tran·am~tter Jointl7 controlling the ··angu.la~ displacements ·ot the cipher wheel: 1~. 

en~ipher~.ng or decipheri~ messages. 

13. · In a cryptogrsph ~mploying in combin·ation: ·• cipher-wheel transQ... . ' 

mitter,~otatable cipher •bee). which bears on its r,im 26 sets of pins ca~ 

·able ot being arranged, as regards their ·being in operative and inoperative 

. . 

positions on the rim, permta1i~veJ,.7 in groups of ~~ve. according to .26 ·of the· 

~2 permutati~na of a S-unit code ~o control the cipher-wheel transmitter, 

and a :Perforated, ke7-tape transmitter,. mes.ns b7 11hic~ said tran~itters 

~oinU.y control the angular d111placemente of said cip~er wheel in ·enciphering or deciphering messages. 

.-2.E"-
.. ·.: .. . · .. 

REF .. ID :-A52 2174 

-~ 

14. In a cryptograph emplo7ing in combination a cipher-wheel trans"" 

mitter, rotatable o·ipher wneel .·11t1ic.h bears on its rim 26 sets Of pins CtlJ>-

abl.e or being t·irranged,as regar~ their being in _operative and inoperative 

positions on the rim, permutatively ii) groups or five·· acco·rding to 26 or tbe· 

32 _permutations or a 5-unit code to cont.rol tne cipher-wheel· transmitter, and 

a perforated, key-tape transmitter., means bJ which said transmitters j_oiatly 

~ontrol the anguPVJr displacements or said cipher whe~l in enciphering or 

.decip~er~ng messages, eai~ ~eans consisting of a_motor-dr.iven coiled-spring, 

a ratcbet"~'seP.ed 

~~ to the c~pber wheel 1 a solenoid, the &"8ature of which 

acts, c>n· the ratche·t and permits the cipher wheel to he displaced an;ularly 

in ~tepwise fashion, the solenoid being .. actuated by ms3')s under the joint 

control of the· ·ciphe·r-wheel transmitter and the. ·perforated, key-tape transmitter. 

l~ .• · In a cryptograph empl.07iog in -combination a cipber-whe.el. transmitter, rQtatable cipher· wheel which bears on its rim ~6 sets. of pins capable 

ot bei·ng arranged, as regards their being ·in operative and inoperative posi• 

tiona on the rim, pennutatively in groups or five according to 26 of .the 32 

permutations of a 5-unit code to control tbe cipher-9beel transmitter, and a 

perforated, Ji:ey-tape trEll'Jsmi~ter, means by which said transm"it"ters Jointly 

control the anguiar displaceme~ts of said cipher ~heel in enciphering or 

decipher.in~, messages, said meii:ns coneisti_ng of a motor-driven coiled spring, 

.. ~ ....... ... 
-· -----."~::·;~ ----:.\ ~~ .... ···-----..._..---·--·--:----. 

. ,/' 

._-.. i!-~"¢~ 

--· - RE-F-:::.-I-B-:-A§-2-2-1 7 4 · · . -----........ ---:·:-.--- ., 

.. -

·,_ 

a ratchet attached to the cipher wheel, a solenoid, the armature or which 

acts on the ratchet and permits the cipher wheel to ·be displaced ang12larly 

in ste·pwise fashion, the aolenoid being .actuated by means under th~ joint 

control of the cipher-wheel transmitter and the p.= rforated, key-tape transmitter, said joint control being according _to the rule that the cipher wheel 

under t·be drive or tbe motor-driven coiled spring ial cauied to be displaced 

angularly i~ stepw~se marJner by the solenoid, the latter ac-ting in conjunction 

with the ratchet until the permutation of pine on tile rim. o! the cipher wheel ··· : 

sets up in the cipher-wheel transmitter a first set of rive portions of an 

electrical path through a first set of five or a group of ten pa.ired contact 

points and associated five conta(:t levere comprising said cipher-whe.el transmitter, said first set of rive portions or an electri·cal path exactly matching 

~~-~ 

a sec.ond and similar set or five port:l:ons ot /\.the same elec·trical path through 

a second set of .five of a groap of ten paired contact poin·t.e and. &ssociated 

five contact levers controlled by the tape tr~nsmitter, whereupon the cipher 

wbeel is halted ia its rotation. 

16. In .a cryptqgraph employing in com.bination a bank of 2·6 signali~g 

elements, a 26-element ke7board comprising a set ot 26 .contacts tor closing 

· respe::tive circuits to the set ot signaling elements, a plural-unit-code 

key-tape -_transmitter J=ointly controlling _with the keyboard the set of signaling elements, means tor changing the electrical paths between the elements of 

.. μ a.w ;up 4 . .& I I 2 . ··-'- ..... .. s .. a . 
REF Il):A522174 

" .. ..... --·· -·.-. -. ___ ..;..._ ... ·-=---... --- -~--~~"'7·---:"''"--:"";"" -·---··-·- --:-· 

·. :· . 

. . 

. . : 

the keyboard and the e lemente of the bank of signaling. e-lemente, e~d- means 

~onsisting of .·a .cipher wheel with a first se .. t · ot 26·--c-ontac_t.a eq11idist..antly 

dist-ributed· on the ,obverse face of the cipher wheel, a second and· homologous 

set of' 26 contacts equidistantly d·istri"buted on the reverse face of t:he _cipher 

. ' whe_el, insulated condllctors· passing throagh the cipher wheel and. connecting 

the contacts of tbe obver.se face respectively v.iith the .contacts· of the reverse 

face., on the rim o.f the cipher whee.l 26 sets of pins caJLpable of' being arranged 

in operative and inoperative positions according to the permutation~ ··or a. 5-unit 

. . 

code1 a cipher:-wheel transmitter comprising a firs-t set of five vibrating contsc-1; levers actuated by the penliutative~y pos1t·ioned -pins on the rim or the 

c·lpher wheel to a·et up through the contact leYere and five or their. associated 

t.en paired contact po-inte a first set. or five portio·ns or an elect.ri~al _path 

ror the control of the angular displacement or the cipher wheel, a second set 

of five vibrating contact levers actuated by the plural•unit~co4e key-tape· 

transmitter to set up through the five key.,,tape transmitter contact ·levers 

rmd five of' the-ir associated ten paired contact points a second set of five 

~~~~ portions of khe .same ele~t.r-ical path f"or the control .of the angular disp_lacement of the cipher wheel, means· ror impar"liing to the cipher. wheel a rotatory 

movement, latter mea..-is being under control ot ·said electrical path, said ,,:.:: ... ~-· 

co~t.rol ·being accoi-~in_g to t~e rule that ·the angular displacement of the cipher 

. . : ~ 

wheel· continues until the first set of five portions of said electrical path 

exactly matches the second set of portions. 

--'l8 - ......... .,,...;.. .. • 0 •. o"• •o 0" •o""l"" "R • 0 
. --- ··-· -··----·- . -· .. REF ID: A522.1.7. 4 

,/.-....._ r'--. 

J,'1 •.. ID a cryptograpb, the method of enciphering w~·i.ch consists io continuou~ly varying the cipher resultant of a given plain•te~t character by externalLy controlling t.he angular displ-acements of t1. :rotatable, c71indrical connection•changing device. inte·rposed between the· e.lement upon which the plain•· 

1J1hich 

text ch&raoter is established and the element upoiV'tbe ·ci·pher charact.er is indicated. 

18-•... I'n a cryptog_raph, the method ·or enciphering which consists ·i,n continμously varying the cipher resultant or a given plain-text char•ct~r by externalling controlling the an~lar c;iiepl.acements or. a rotatab~e, cy~indricsl ·connectio11-.changing device inter.posed ·betwee·n the element upon which the- plaintext char&cter is established and "the element upon which the cipher· character 

is. indicated, said external control cunsiSting in using an electrical· ~rans;.._ 

mitte_r through \lhieh is paeeed a· perforated tape bearing perforations cor.res-

.·· . ·.:-·· 

pond~ng t·o an unintelligible, random sequ,u:ice- of characters in a· plural-unit-code. 

> ·19. In a cryptograph, the met.hod or enciphering which consists in continu~ 

ou.ely varying the cipher resulta11t of a given plain•te.xt_ ,churacte-r ·111 externally 

controlling the· angu.~o.~ dieplacem~nts of o. rot11.table, c_ylindrical connection• 

changing device i.nterpoaed bctwet:n the e-ler:ien:t upon which the I>l~in•text ch:araeter• 

is established a.tld the element upon-whic.h the· cipher character is· indicated• said 

ell:terne.l co11trol consisting in using an electrical tranom~t_ter thr-ou3b_ which is 

passed a perforiated tape get&ring perforations· corresponding_ to an unintelligible, 

. -l~-
REF ID:A522174 

·~ -!> -·~ -

rand.om s·equerice of chara~tere io a plural~uni-;•code; _and constantly c~angillg 

eaid tape. 

20. _In a cryp·tograp~, the me~hod .or enciphering which consists in cori- . 

• . . 

~inou8.ly varyi.ng the cipher resultant of a given plain-text character by ·extezoriaU_ing controlling the an3u.lar displacemenes or a rotatable, cylindrical connect~oa-changiag device interposed between the element upon which the plain• 

text character is estab.Ushed and the ele-ment upon vrhich the ciphe.r ·character 

is indicated,. said external control consi.e.ting in using en. electrical trans-· 

. . . 

mi_tter through which is p-asaed a perforated_ tape bearing perforations correa-

~ooding to an unintelligibl~, random aequence of characters in a plural-unit• 

c~de.; constantly changing said. tape.; and making said tape coextensive. in ~eng~ 

·with t~e le~~h of the message to be enciphered. 

21. In a cryptograph, the method ·ot ellci.phering which cons.is.ts: i.n con"" 

t_inuously ·varying the cipher resultant of a given .plain-text _charo.cte.r by e:x-

. . 

ternally controlling the angular displac;:~ments of a rotatabl,e,_ :c_ylindrical connection..:chtt.ng:i,ng device inter?,osed ~etw~en. the .element u.po~ wbic.b the .pU.in•teilt 

character is establish~d ~Eid the_ eleme.n~_upon v,ihicb. the :i:1 .. phe-rtcharac.te_r ie .. in"" 

dic.ot,ed, .said e~t.ernal -~9_ni_ro~· .consi~t_ing in using an electr.ical tranemit~er 

: ~ 

through -which ie pe.ss_ed a.··perfora~ed tape beari.ng pertoraioioni:: corr.~:;ponding .. . . . ' . . .. . 

' . . ! 

t_o an unint~lligible, ra~d~m. s·e.~uene.~ of c}'lars.cter-s in. a plural·u~i t!"'.~ode; 

' 

i 

;. ·~ · .. 

' -

constantly changing said 7~pe; ~~d mak"ing said ta.pe coextenaive in ~ength· 

l : . 

"@._. ... ,. :::i:.f.:s:;: ... ~-.. ~.,;.r.,, ·-· ...... ; :···· ft. . ..... >.·<e· .J. _e ......... $44 .WWW ...... ~·· ... JC. 
,,---._--· -~ .· ·--,--- ______ -·· RJ;:_F ID. :.A522.l 7 4 .. ~-------.. ~ ... = .. -~ .. :~.-~, -------~ 

.· ; 

.;. __ 

OONFIDENTTAI; "'' 

,.:1 

with the total lengths of the .set or messages to be enciphered. 

22.o In a cryptograph, the method or enciphering which c·onsiats in 

.-continuously varying the cipher resultant ot a e;iv~.n plain-text character 

by -externally. controlling the angular displacements. of a rot~table, cylin• ....... ::,, 

drical c-onnection-changing device. interposed bet~een the element upon_ which 

the plain-text character is established and the element upon which the cipher 

character is indicated~ said external control consisting in usirig an elsctrical 

tran~mitter through wh~cb is passed a perforated tape bearing pe rforatione corresponding to an unintell~gible., random sequence of characters in a plural-unit 

code.; constantly changing said tape; making said tape coextensive in leng-t;h 

oith th~ total lengths of the. set of messages to be 'encip~ered; and constantly c·hanging ~aid tape with .each dii"ferent set or messages. 

23. In a cryptograph, the method of enciphering which consists in con-

. tinuously varying the cipher resultant of s given pl~in-t·~~t oh.aracter by e:xternally controlling the angular displacement_s or .a rot~;table, cylindrical 

connection-changing device interposed be.t"1Jeen the ~lement upon which the plaintext characte.r is -esiablished and the element upoi:l:.wt'l~h. the· cipher character 

•·•I 

is indicated,· said external cootrol consisti·ng in ... ~si.ng an· electrical trans-

... 

. . . 

mitter through which is passed a perforated ·t~pe.,be(irin~ perforations corres-

.... . ! ··~ .• . ; 

. . i . 

ponding to an unintelligible, ra."ldom sequence o_f- _c·tiar~-Cte.re·-. in a pl~ral-unit• · 

.·· 

.•• • I 

....... 

code; and causing said transmitter to operate joi"nt_iy··-:~/;ith me<:LDS under contro~ 

C01'TFIDENTIAL -3~ - .1 ./ . 

.: .. 
. REF ID.~ AS.22.l.7 4: 

. .-\. ...-... . ·; 

.. , • .·-

., 

or said conr1ection .. chang1·~g device. 

24. Io a cryptograph, the method or enqipherizig which consists· in co·a-. 

tinuously varying the cipher resultant of a given plain-text character by ex~ 

ternally controlling the angular displacements of a rotatable, oyliodrical '. ' 

connection•chang1rig device interposed between th& element upon which the plain• 

text cbaracie.r is· established and the element upon vihich the cipher character 

is indicated, said external control. consisting in using an electrical trans-

.mitter thr.ot.igh which is passed a perforated tape bee.ring perfo.ratiune co1•responding to an unintelligible, random sequence or characters in a pl~ral-unit• 

code,; and causing said transmitter "to operate jointly with means under control 

of· the connection-changing device·," latter means consisting of a :tranamitter con~ 

trolled by. pins projecting from the rim o-f the connec·tion•changing device. 

25. In a cryptog·raph, the ·method or e·nciphering which consists in con• 

tinuously varJing the cipher resultant or a give·n plain~text .character by externally controlling the angular displacements of .a rotatable, .c·ylindl'ical 

connection-changing device interposed· between the element upon .whd.ch· the plain 

text charac.ter ie established and the· element upon which the cipher character 

ia indicat·ed, said ttxte.rnal control. c~nsisting in using Q.11 electrical trans., 

mittcr through which is pe.sae·d a pert.orated tape bearing _p~rforationa eorres•. 

pqnding to. au unintelligible~ random sequence of characters in :a plural-unitcode; causing said transmitter to operate jointly with means under.control of 

said connection-changing device, latter means consisting of a transmitter c·on-

.. 3~ 

cs .. :P•. ·.- ¢14Lc '\!l:F.... at a:~l .. c .. -.. c_ ... c:s .. .• · ... - --. 'f'I?' ¥ I . ), A. ¥.JES . .,S . . r;r .... ·'. .. > .Qi :· 
-~------·--· . -----------···----·---·-·---REF ID ":.A52217-4-----------··~~-·-~:-· ---- ·:-· 

trolled by pins projecting from,, the rim of the connection-changing device; and 

be 

causing said pi.ns to/arranged in. sets in operative· and -~aoperat.ive positions cer-

-.responding to permutations or a plural-unit-code.· 

26. In a cr~ptograph, the method of enciphering which consists in cont·iauously varying the cipher resultant of a given plain-text charac·ter by ex-

. ercising a two-phase ·control over the angular displacements of a rotatable, 

·cylindrical" connection-changing device interposed between the element upon 

which tbe plain-te.xt character is·.establisbed o.nd the element upon which the 

cipher character is established; causing one phase. of said two-phase c·ontrol 

' : to be· exercised by an element which is external to the c ryptograph itself; 

and Causing the other phaiH to be exe~ised· by an element which is a Umber 

·.or the cryptograJ>h• . 

27. · In __ a cryptograph, the method ot ·enciphering which core ists in cop. . . . 

tinuous ly varying the c_ipher resultant .of a giVen plai.&otext character ·by e·xercising a two-phase control over the. angular displaceme_nts of a rot·atable, 

cylindrica.l connection-changing devi~e interposed betwe~n :the d.ement upon· 'l?lhich · 

the plain:-te.xt character is established a.ad the el~ment upon whi.dh the ci.pher 

character is established; causing one phase of said two•phaae control to be 

exercised by an element which is e~ternal to the cryptograph itself, said phase 

consisting in using a first electrical transmit·ter through which is passed a 

perforate-d tape bearing perforations corresponding to .an unintelligible, random 

-as-

_, 

' 

. ~ 
~-··- REF·· rD :·-A52-2-17-4: 

.A 

-sequence of-characters in a plural•unit code; causing the other phase or 

said. two-phase control to be e~ercised by en elnent wdch is internal to the 

·cryptograph itself, the latter phase consisting -in. using a s-econd electrical 

traneaitter controlled by pins which project froDl the rim of the conr.ecti-onchanging device, said pins being a~ranged in permutations corre~ponding to 

26 letters ·of··a pluml-anit code·; -and causing the first and second transmitters to interact in Jointly controlling a s·olenoid, said solenoid being 

· ·so· positioned emd actuat·ed as to control the successive angular displacements 

ot the ·connection•changi·ng device. 

·2a. In a cryptograph employing as one or its keying elements a tape 

transmitter through which." ie. pass-e-d a. key- tape bearing p.ertoru.tions permute.d 

in accordance with a tive•unit code• the method of eltminating from the final 

c~yptograms thosE si~ permutations or said code ehicb have- no sta.~dard equ~-

valente in the fiiorse code, said method· consisting in ~-aueing ·tb-e ~ey·t~pe 

transmitter .to interact with a se~ond transmitte.r whic·h ia entirely -inde_pendent 

of c·ontro_l. by the message character. 

29. In a cryptograph employing as one of its- ke-ying e·lements a tape 

transll:i.itter through which is passed a key t.ap e bearing '12 r-foratio.ne permuted 

in acoordnce with a five-unit code, the method ot ·eliminating from t ne: fin~l 

cryptograms those· six .pen:mtatione of said code. wh.ieh ha.we no standard equiValente in the llors~ c.ode, said meth.od consisting :i.n causing said key-tape 

transmitter to serve as a means of opening and closing a' set of five in-

- 3~- - . 
,------~---·-----'---. i ---,._....,.- ···--REF ... ID :·AS-2-2-1·::7-4---- -----·----·----··. ·---

.A . ..,... -·.~ 

depend6nt circuit breaking elements of a single electric.al circ·uit having 

a set of-ten such independent c~rcuit~breaking elements. 

30.. In· a ·cryptograph -employing il first t-ransm.itt.er control,led by a. 

rotatable• ·cylindrical connect:io11•changing -device a.nd a second tran·smitter · 

cont.rolle.d by a. perforated key -taps bearing perfora~~ons· permuted.-in accord• 

ance 1lllith a five.•unit code·, a·aid key tape serving as the keying e leme.nt f·or 

cip~ering, the method Of· eUminating from the final c_rypt~groinf! tn:ose" six· 

permutations of said· five-unit code· which -have n'o atandard equivalents-" in··: 

jointly .as· a means er· opening ena closing a si_ngl:e- e le.ctrie.al ~-ire_~~~'{ having 

. . .: . :.'~ 

ten independe!lt. ci~.uit-breakina ele·ments: arranged i"n two sets or_/ii-t..e, the 

.· .· 

first set ,being control.led by one of said. transmitter~;· the second s·et beicg 

controlled by the otber transmitter. 

."·· : 

• 
...........--···- ns. 3' 

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B 5 ·.~a :· >- ~ 1· .,. :s " - ::: · u ·. o ·. · . N ~~t· 

ti" - . : "J'U . . -. . ... ,., · .. •· ·< .,.. \.I· f.:! . •. ~: .;... 

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{~QQQQQQQ. 

G) G) Q Q.Q Q Q Q:C0 

'· 

.. QQQQQQQ . . ,....,_ _____________ ··--·· ·.--·· -· -··---. ··- . ---·--· -·- -··.. . . ____________ _..,... 

···-· ______ ··- ___ ____ Et~ £ . -·-·-·- -·-·--- - -- ··-·- -----· - ·-·-··_---..:._.-.. ---·--·---· ·-··. --·-·. --·-. _: ----· ---- --~ --- ... ..:..