I 

_, ~ ' . 

'·'· . '· •.. 

REF ID:A522105 

WAR DEPARTMENT 

ala 

4 ~ ,J -a-_..(_.~ 

CO,'t:'f1F~1\P\L l i' ~ u .... , 

OFFICE OF THE CHIEF SIGNAL OFFICER 

WASHINGTON 

llU'Oh •• 1933 

-..Sor heh lltaa..U, Ottioer-J.D...Charie, 

baearoh 6 hftl.opunt 1>1v1aioe. 

Attaobed hereto 1• a rtn'ieed report, in du~lioate, 

on Sipal Cori>• Converter, T7Pe 1-134, •hioh will be of interest 

to TOO and to tb.i Si.pal Corps Laboratoriea at Fort i£011J1outh. 

s. a. J.kin, 

MaJor, Signal Corpe. 

t: ;_· ' ' u ~- i .. .i .Ii \ L,., 

Peclassified and approved for release by NSA on 11-19-2013 pursuant to E.O. 1352§ 
REF ID:A522105 

1. .A t.est of the cipbf:r machine diaclos.ed t!~e rollowing1 

.!.• spee.d. 

(1) The mazimua mechanica&l speed of the uch.ine, detemin.ed 

by depreesin~ the E•~"'T.e key rE peL,trdty ~tld as rupidl.y oo possible, 

(~) The maximum ap~eu of encipher~ent or deciph~r.~ent ty 

time, approxim~tely fiv~ mi&~teo, ie 30 letters JGr minute. 

(3) The oversge speed of en~ipherment or deciphe!"!lent by 

an opt:t'~t.or workini) in u ~tt·caiical ma::r•!r for ;;; ftairly long 

period, &(.'lproaini•Jt.ely 30 minutee, b 25 lett~rs ~c;r :ninute. ':his 

a~~r~ge is b~sed unon the actual encirherment ~nd deoi~herment of 

1dth tte !)ivieion Field Coclf-, asit'lg portions ot the fl_uae text r.s 

ubove, showed th.lit the ci9her m~chinEi ie upp.rozim~tel; twic~ ~• 

f'&£t ~a ti&e t.•94 dHiee, but 110 !"'t-~ter Uum the. !iivis.ion field 

Code. 

(5) l\trther ren~rks on ~he eubject of ~r~~d will be fcuod 

1• i\eliubility. 

In eea£rul it mu,y be a:.;.id th~t. the t\ucbinE: is q..ii·~e nl1;.ible 

in ope:-• ..-t.icm, but the f'ol.lowin~ mechL.::.sie11l fe.iluree •4]Er& noted du.ring 

t~~e test1 

u!ti.=r depresoing: 1 the cipher whef-1 occ~6i·.m~:lly !dle tC' rotute 

to b& cu.used b) '°"'ulty i..lCtioo of' ·f..hc. tppe-eteppia;; mect.unis:n, t.Dd 

rer.ders all subse ·iut:nt tExt incorrect. .fn nom~l op•riotioo or the 

.·· .... -... •I ~. j ..• I •• ·:· : '• 

. . • ' .· • .I r. Ii..>' !_ ~ , .. 1-, • •• • 
·-

(2) OccGaio~all7, the cipher wbe~l ie·brcu~ht to~ atop in 

• poeiUon •li~htlJ o!"f tbHt rt1:•ired to bring the cont11.cta on the 

•heel in Jutapoeition i.;;iib thoee oa the fixed diaca between wticb 

it ra~ol·na. ~·.cen ti.:.h hL ;···ens the lwm!'• •ill fail to U3ht and the 

cipner wheel must be ~inn ~ sli:;bt push by hsnd iu ord~r to esti-..blish contact for lamp indic~tlon. 

(3) Unleaa the perfor~t.ions in the keyt~pe ~r6 accur~tely 

plac~ci ·.!.'!th reepec-t to ~~he r:iios of' the leyt14~e trane::dtter, the-re 

will be occi.Dieus wt.en the tr:.i~.ifr::iitter pine will lJe si:;t up .i'or a 

permutation either net repreccmtcd on th~ cipi·wr ·;.iheel, or not 

correci ·:. i th respect t.o the t;..!>C• ·:J.i.&n thiB l::;;;p~ena the clt-:hr:; r 

wheel, in the firet Cf-.l::se, 1Sill r.ot frtop revclvin.b, f.J;d ill the 

second c-.;;~-e, wiU&-;c;? ..,:; ~n ir1ccrrect ~oeitiC1n. ;;bile tbe first 

not tappen, or it it did, rEtlaincd un~o~iced, ~c it involves 

only c. sin~~le-letter error • 

.!• .<>.ecu1"1 ty. 

Theor6ticc..U.y, ·the rn;.:cb~l•e c~m be uEed to :>roda<:<" cryp-to:~ru."!ls 

repreaeutin:~ ~ l"andoe-~ixed acq~.::.ence coiru:ident in leu,:;t.h dt.h the 

ob?iously in'9ohe greut diffit:ulties ir1 practice ~ith rc.;;ur.d to 

the ;;rct:iuction, distribution. ;,,;ttd ~anipuhtion of' ke7-tuI>eG nong 

sr...~es, ~D iJccu:nul.:..tion of tri..fiia tb;.;.t ie 2olv1.1ble ·d tho:.it ;JOIcomwnie:r;tions ~ecrecy for :;;or" thca <! f'ew hcura mu~t be mdnLained. 
REF ID:A522105 

·~ 

2. !-h• followin~ comf.1fnts ere mode; 

.!• Th• pne.t:Dt liriit-i;iticn Oll ~he speEd Of Opfriii"'..i<lD of· 'the !ll~Chine 

optration -'O~tld u.11do11bttdly be inare .. :eed, ~:iut t.o •.,,a.:.;~ ex ;&n-~ c111mot 

tir.tl!.; lost in ~!'enent ope:-t:tio.{I ie due to th£ nece::;si~y for j.'aitin.; 

\a varir:.ble .len~th er ti~e- in eui:h cr-se) until the cipher· Eheel h:.aa 

of rJuch :; .fe:,t·n·e by freein·J it, if ~o~sible, of the inc!i~::t~d limit~-

~nd dii'~icultie:s of tspe ·~rc·.l~tcf.icn, •Jistri!mticn, ,.rid ::i.:::.:aipubticn. 

····-·-----· ---------
REF ID:A522105 

ho nab aod1t1caUoaa hue al.re~ IUU•etea th••elna. Britt lt 

ia bellend that~· ~Hilt cleat,p otters llt.tl• poaaild.l.U.7 tor 

iacrnlbg the .a_peed Of opw&tia to t.h& DGCUNl7 111niaa. 6o cha--

actera per m.J.nuteJ and it is aate to •9 tbat the dealrable O.i)timm, 

200 to 250 eharactel'a per ailmte,. c:ould lleYlll" be attal.aed bJ" a 11&eh11le 

epwat-ing u?Qn the pre&elft. ?J!'iad.pl~ ot aa irregul.arq d1•placed 

ciphw wheel.. 

3.. lt ebould. be 'bone in lllf.nd tb.e.t ttw present dnelo_,aeat is to be r•ardecl 

u repres&Ung the initial• mr.per...-ntal i-'baaes of s poJect to produce a 

ate, eutout1e, rspid cryptogr~ Uthe fi:r.st .model thus ~rocmaed ;reaen.ta 

dafect.t aac. dlaadTwrtages this la not rmre than il1ght be e.qected in a field 

where l&8DJ uiala have been •ade bf OOJU1etc1al interests with litU• or M 

sucaesa thus rar, because 210 tar as is ·known,. ao mt011atic cipher sachin.e• 

tlhile the mod.el prodnced ..,,. the Laboratories Z'8J)r81eta a .t'in.e p1.eee or .... 

aineeri.D.g ekl.ll ad ncbaaical worlalar&abip, the detects and d11act.mitq:e1 

t\I01Ated out abo.-e1 espeeialJT 111 regard to speed ot oper&tJ.oD1 ere nch u 

to- lead to t.hcs !ollowia& aonclusionaa 

,a. The preun1. :aodel SlcNld. be regarded aa a aeehan1a relUlting 

from prel.illi.DU'J' uper.S..-t.•t and ehow-3the pou1'bU1t.t.ea and ·l..Udt.ati.ons ot @e tiype of cm gn. 

b. In the belief that- the llllitatiou of the·preHAt model are -

serious aad ditfic:.ult. 1f not 111pose1ble to ovarcaa in s aacbine 

intended for actual service where speed 1.a an. eaaeatial factor,. the 

? <:. tio. aem,ple .uclU.ucs thua fa ;Jroduced abould be Ht. as1.de tfi&i,lOrarU,- "· .• 

ad turther work on thla t.J'~e· ot design sboal.d be na~endc-d. It 1181' 

well be that. in the nur future e,ecial use can be tO"".md t·or thi• 

model, in offices whera speed is :not l'Jl &eatmt.1.tl factor in .secret 

COIUllD1ca.tions. 

--- -----~---· ·-"~---_____ , ______ _ 
REF ID:A522105 

.2• A dttf'erat. bu.ic de•tP mo..dd at once M atUO.S.ed• -qi'b a 

vi•• to OYRCOllbi tb• l1111tat1ons of' ·tJle first de-lip. 

4• lAallBIOh ••it •-• ad.Tisable to ehu&• the l:Nltdc deaign o£ the •M:hbe. 

aarias coaaidel"atioa &.~ouli be tivan to the Pf>••Unlitlea ot the sch .. outUmtd ln the attached descr1pUon (entitled -rlle Propoeed Bev C1"7J>tograph•) 

ad KCGaiJU71a& photoatat of a s;rBtea beuiag ach re1eabl.aace to the ~•seat 

dne~t but 11bieh, 1t is bellned~ otters 11aola greater auh'an.teges then 

dots• the iJ'reaSR:t. model. It is l:aell-i-"fed that not Olll1' could the newl.7 9ro;1osed 

qetea be operated. u tut. •• a tnist coul4 uuli'\ll&te a kqword, mt. al• 

the degree of cry~ogr:aamic secu1"1:i7 atfmtdad Jw- the uee of ~&lati"f'eq Short 

k~apea hr ill ·coiumic•ts Oft1" a period of ·~ da7s would bu sutficim 

-ror cOlllllmdcat.icma exchanged 'betlr.._"D ena tho. highest headquarters. In ttr1• 

Way tbe dU'f1cul.Ue8 tJr hpe :i>l90ciuct1.0ll anQ di!SV.imtion lWCTtlJ.d USO be 

aTo1ciad. I11 £.set. the =advmtage-11 off'ered 1JT the i'Nll•lted •• aodol9 aa Mt 

forth in the attached description~ are belleYOd to be EIO great aa to 11srraut the 

iD1ttat1oa of ork OD the production ot. Reh a e:.odel at th.6 eerlleJtt ;oasibl..e 

moaent. Thia ts urge.ntl.7 racoau.ndetl. Tbls office can furnish a mubin&. 

which •ill, it ia bel10Tal1 nat.U.q lend 1taelt to lllOtiticatlon fo1! tho our-

~··• in ahd. All that would be nece••a?7 •oul.d be to add t·o it. the pressn~ 

kv-t.a,ile tranSI.11.t.ter, .fin ma,gnets 6Jlti. u&.1Clated deel....t.epping aechaai·s• 

consisti:ng -or aba;;tl.e lnera actiq ~q UPQD th11J preaut cipb.e.r wbeel.s. 

The modl.£1cat1~ 81Ji(geat.ed Jid.ght ·be accomplished 1n this aaDDer within • ab.on 

U..e a.;sd witllaat diff'iculty. 

s. It 1is .t\Jrther .recoaaett.ded that it ii-Wk oa th.e ,_.""Oli<JSed 1rtnti131 attaclueu.'t 

hall not ,..t been coa'llUced, it be delqed until a Hdel of th-e 11ew t1}J<e hu· 

been produce4, as it _, irafluence tr.e deal&• of t,tie printing attachMllt • 

-·' .... 

. : :" \. i . • . 

·...,,.~~~-.; ··~J -i~ . .i 1c,(: .- ·~ ;:\ 1 

........ . -.;...-i:-=-.:.----=---r-r-·..,.._-='--- --- -·---·-·~ .. ~-----~-----···-~---·--·-· - ....... : . ...... . 
/ 

REF ID:A522105 

CONFIDENTIAL 

proL)Osed neu cry_vto~r«'t;h, t.here are sho'i"D the following elements all of which 

are w~ll-icn.own in th& srt ap._:ilic:t.ble to :aodern ceyptogrli.?hs: 1 1 a stedard 

typewriter keyboard 1}rovided with a eet of 26 keJ"IJ !or closint: a set 0£ :26 

contact.a correst'ondinc to the ~6 l.etters oft.he a.lt'habet; 2, a :$et.of 26 

indicatine dov-leee which may t&ke the form oi' m~nets of a. ~_,rinting me-ebaniSl:l 

or of lit.hts to indicate by illumin!l.tbn the e~;uival.ents resulti.nr .from encipherment or deciphernent; .3_, l!l ast o.f five rot~table; circuit chsni~er£ constructud ln 

the fon of ciphei, 'l'heel.s 111ounted U)On n ear.aon .shaft and arranged :tn Jtuc.ta;oaitlon to ~)rovi<le a l~rze series of variable ;~ths for the p-assage of al.Mtr!ic. eurrents representilli :i:cssage- eharsetera, the exact path in each inst.If.nee being 

diotermin€a by the relative rotatory z)OBi tion of th(;: wtolc set. of ci;.1lu:r wh~e.ls 

at that lnste-.nt.; tind /,, 1 ·a. ta,;;>e trans•itter of thf; tJ;e em;iloyed in Baudot syst&:ss 

of c:>rinting tcle&raphy. In ~dition to these. vull mown e:le11en.ts, there is shown 

a eet of five :ttl{;nets, 5, and a connection chancer, 6,. th<:: ,.7..irpO$O of which w111 

now be e:x;>l<.U.nt.d. · 

!n all thi3 previous cr,,;-tOGraph;~ based. upon the use of rotat'.iblo cipher 

1lheels of the ty;.:JE: referred to above, nnci a'.i."ranf,cc;. a."'! im1iceted, tht: .i4.enncr e•:tbodied in t.hose cr)9toil'Rt)hs for cht:illfing the rclati ve rot.ilto17 ,?OtSi tions of the 

ci~Jhsr ~heele are of e definite and predetermined character. For example, 1n 

Hebern, u.a. Patent No .. i,633-1 072, t..1le fixed cl1sracter of tho sucaesei•e rotatory 

moveaents of the cipher wheels ie e;,:plained in c;u1te a detail~d aanner, anti th• 

srune is true aa r;,;~gards si.uilnr CT'Jt.>tot;rc,phs proaueeu abroad. This invar1abillt;,r 

of Jaotion )roauces, hO"'.t·eve.r, predictable rcla.tbns.bi.:>l' between the plain-text 

characters m'l.d tl'H:) cii'her eh~il".f_;_cters for r.i.ny given initial arrMgeraent of the 

into tht.: hands of un~nth.o:ri:ed ~n1rtie3, the latte:- Crlll ;ilsce thE;Mselvcs in a 

£looltion to lieci;hcr the message:; lar1:ely tt3 &. remilt 01' the ~redetermined 

nature of tht; :mccessive rotatory dlsJ:}la.c£illents of the: cipher wheels. 
REF ID:A522105 

of a variable lftechanislll .for dis~lacing the ci.~er wheels f'or the tixed aeehanim ref erred to abovo·, ~.nd th.is i!t aecom?llshed by llfH'lllS of thf' t&pe trrns-

.:aittt:?r1 4, and th~ 15~t of five zagnota; 5, controlled by the t~pe trt:mmitter. 

Tape tr:mmitter, I.., con3irl:!:! of the usual fiv1:t moTable contact! 

iJondiog to a rtJ.nc.l.ori, unintvlligib1e sei-luonce of charu.cter3 in ti:.<; Bm.td.ot cade. 

The ,?erfo.riat:ii>ns control the r..ction of the 1·1 vo contact !l!alllbers, 6-1:), which, 

i;n turn, control thf.; action of thG five !\le{';net:::~ ll, 1:2, 13, ll:t 15, aa ~ aet 

ne·t.s,l.l-15, fillU circuit. bret>.ke:rs,. 6-101 .i.f! also eubjtict to varia:tion thz·out;h 

the c0<nnection cklr.fuer, 16~ which. ia simllar lu foriu and f.unctlon to the:t dis16 in Fi~;u1·c 11 ~;here conductor 17 ls con.neeted., throuc;;h t.he switcl.bo!ird 16, 

to conductor 2J by & ;ilut and j B.ck arrangement, conductor 18> to conductor 22, 

anti. so on, the ~t'f ect of the μas:'!ege of Baudot character + - - - + would be to 

actuate marneta 12 and 11, l'~SJ)E:Ctively, eriuiv~lent to the Bauciot chnr!':!lcter 

- f f - -· 

The :n.a-Gnata .ll~to 15, control,. re.J;icctlvely, the displaceaent in st.e;?-Yiae 

::imnner, of the -ci.tJl1er vhEtela 27 to Jl, <.nci thus deter!lline the rotatory t>Oai ti one 

of the five ci_j)her ~heals in unci.llherill6nt or ueci,.>her21ent. It iil ~..sS".wed natidentically-, r:i.nci .t)rovlded ·d t~: identical key trtpe.J for controlling the iROve:aent1 

oi: t.h.e ci;>hsr wheels. Tho exact i:nltittl settings of t.he cipher wheels• tha per-

!he ;irorklng arrt".nge:ae.nt may be woh that on the back stroke of ar..,-

key of th& J.:t.7board, fl cont.act" cuntrolled by a un.lvere:al bar on the keyboard 

is closeu, ~nd the circuit for operatinc th~ t~pc ate,?-forwsrd zat;net is closed. 

ll tc 15, are oper!'.ted end the citib.er 'ithenls are f.'!et. t':I a na'A' Jos.t:tion .for the 

·enci~>heri.iient (or deei,}herm,;;.nt) of' tht! next chxrru:tar of urn ;rios!ag~ • 

.... 2-
REF ID:A522105 

Since the cipher equivalent !'or a letter depende u?On t.ht:: rotator;r 

variability by iHMs o.f the eonnecti1.>n chMgor, 16, it i;:i obvion:it that for 

the SMe key t~pc set s.t the same iui.titl i)v.1.nt t:.w cipher r~sultant.ir will be 

different for each pormutati~n set up at 16. Again, with tbe &rulle pe1·mut.ution 

foT each different inith~l setting of the key t;:.~c. In addition to these 

In order to provide .fol'"' ~;uival.:mcy bctwe:l1 encii)herr;:icnt ~.ni deci/bermtlnt, there must be interp;;>sed. bet."i¥th .. "tl the ~hole e:et.; ol connoct.i-;ma leading 

fl'Oj!l the k'!i'ybo.r....rd snd tJ:.c whole set of conne:ctions les.d:Lng to th.e :ar..g:nets of 

actue.tt-.:d by fi. scretr, can be :10vad to establish one ::Jl" the othe1· s€t of connection a 

:i.s rcG.u1red for enei~fr'!eroaent; or de:::i~h.e.r~ent. This me?.JlS is, holicver, not novel 

end alreu<.\y e.tl :.'tl1t in !l.t least ont:! cryμtogre.)h ?..lrue.Oy on th.o ~p.J.•ket • 

.A vary :Lcl{Jortant ndvs.ntage wh.lch this ey3te~ offers i~ thnt it will 

~ler.mit of \leing two keytape tr~.nmitters a:s~ociated in an lnter.'.'.\ctlnt relatlanahip, 

Ci~er Gystuill. Thus, by e111;loyi~E two keytElpe transmitt..ers controllod by two 

a resul'Uzlt. sine.le key of 9300 eleiK;nts can b~ bx·aut:ht into .;>l~ to actuate tbe 

cipher 'ii'hedz ':..7 t:) 31. A t&pc eont:dning 100 B&ldot c.hs.rtict.cra ie ap)roxia&tely 

10 lnches in lt.lnt:th, so that such t:9es -aou.lc:L involve very little diff.i.culty ii'! 

..>roduction~ dietrib'iltion rui:.i. hand.ling. iloreover, th~ !.llEH!.h!lllls:a of the cry.,?t~grrsphic: 

;:iy:stem. ls, in thia case, such that the fitct th~t two intorleting, revolYint 
REF ID:A522105 

CONF:BENTIAL 

keytapea are etn;;loye.d to ~roduee a aingle re3Ultem:t, key cioes not, ,1..1a in the 

which oan lend to solution of !fle.!lsages wlthout the key. 

Wit~~· :t. o-AA-~~-~ 

o,c .~ .. ,. 0 ·~lk~t': 

~. ~,\1)) 

·~ ; . ···: .... ·-· . ·.r..a •, .~.· ·. "\ t . ;, • 

""·' :.~~· .. ; '..i ~ :t ~-ti .. -.. ~ \ .• 3 ~.i---e.1r._. 
1',! 

"= ... •,!! •• .REF .ID:A522.10' CONFiDENTIAl 

Contacts a, b,.c, and d (four of a set of ;2 sind:lar contacts) are 

all mounted upon the same plate which can be moved t~- the left or to the 

right of neutral position shown. When plate is moved to right, ·contacts 

are made for enciphering; when moved to left, for.deciphering. Thus, if 

in enciphering A (Plain) = Y (Cipher), then I (Cipher) =A (Plain) in deciphering.· 

I 

I 

I 

... 

., 

I 

I 

·1r-··-·} '.. . \ .. . J· .·,,, l ; . 

I 

I 

I 

I 

. , . , 

,/' 

\ 

\ 

' I 

\ 

I 

\· 

I 

I 

I 

~ 

,, '' c· 1;-!.--·, ... . ...,,... ... •·i·r .. .. ..;= •• w.,a!J'"'.,. .-------------. 

. i .. 

I 

I 

I 

I 

I 

I '·' I \ I ', . ' \ 

I 

' LJ -~ 

·11y11.: ·,)\'' 

'------'"__ .. -:_..___[ -'"----ll~l·ll--·. _ _,__ 

•'. 

· .. ··: .. ·~ .. :~:TiGURE.B .... 

"y''