REF ID:A4148864 

Address reply to 

CHIEF SIGNAL 

Washington, 

OFFICER 

D. 

OF 

C. 

THE ARMY, • 

WAR DEPARTMENT. 

~i..neerin..:; DIVISION 

ard Res ec.rc h 

OFFICE OF THE CHIEF SIGNAL OFFICER. 

WASHINCiTON. 

jo:n:ho 10 December, 1919 

Lly cle::~r (.; o lone 1 la byan: 

Your telet-.;r<:Jir. of G.OO p.m. of the 0th was recoi ved here a.tout 

noon, ti!e 9th. ~:'our force is undoubtedly to l:e cong'r<.i.t...i:W.ted upon 

the Cieci..;_iherma1t of ti-a rnessa-~;~ wi·1ich ~,:ou c.-.rn1ounce in y.jur telegrar:·,. 

I ta.i<:e off rr.y ~1::1.t to ;\iverbanJd 

• ':.'he <.id.di tiorial tc.pes which -.-.. e ·:;ere to ~;end have been re~dy 

for sev0r2.1 da~,rs, but on acoollll.t of tJ-1e pressure of oti·&::r business 

t!1e,y have not been rr-..:.iled. In view of :1our telegr<:.rn they will not 

be sent to you. 

In comiection with your study of the decipherment. of trese 

mess::::.r;es "i:lictJ. 7ou wmounce, t!1is office is interested in securing 

from you an accurate and complete s ta tei:ant as to the following 

facts: 

1. '.ius tl:e deci~)herr:ient carried out exactly as rroposed in your 

rru.:.nuscript furni sils3 u tl1is off ice'? ·.vus any other ~ethod employed 

and if so, ti1e details thereof? 

2. .ihat infon.ution, if any, other than that furnished by this 

office, did you acquire "'1hich assisted ;1ou in tre solution of these 

messaces't 

You r:-ia;/ .:_Jermy>s smile t~t tl1is question, but }:)10·,·;ing your 

lletective i..nstincts and some of the ramific;;,.tions of your system 

which can place o~""Jer;;.tors in t:,"Ov0rn1rent ciepc...rtments, I am rather 

curious to know whether you resc..rted to a.ny such device in this 

case in order to obtain in fornia ti on cone en1 ing these rre s sa:_:;e s, or 

r:.nythine Y1hi ch would le :1d to their dee ii1herment. ' .. :his should be 

a straight forvm.rd acknowledgr.ient on your p::.rt if anything of this 

kind has been done, sirn!)ly to c:ssist us in detennining how far your 

solution did, or did not, depend upon factors which may, or which 

may not be coLmted :ti1on in tre case of the enemy. 

3. All·statenents, if LJny, or su~;gestions for\v-arded by Colonel 

or :;rs. Hitt in connection with tre decipherment of these messages 

as a result of their intir:-..:::.te connection with tltis office, which 

you received duri rir; the course of tl: is experiment and ·:;hich may have 

@'pp roved for Release by NSA on 11-18-2014 pursuantto E .0. 1352a 
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led you to the solution. 

REF ID:A4148864 

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Of course, it is quite rea.sona.ble to s'..lppose ·.,hat ;y"ou have 

net secured any information ot!ler than th:..t·ft<mished by fois office, 

bec<::.use v'e are well aware of the capabilities of' the 01_:er£:.ting force 

at ;:1our Laboratories which !1'.ve alre;,,.clJ 1,·1on intern<'.:.tional renown. 

How th~'t :;ou have a:nnounceci the Ci.ecipherir.ent of the ?tessa.ges, 

'.7e are looidn.g forward to .!_'Jerro!JS receiving s a:-e further in fbl";.!.."-- ti on 

of value in connection with t11e o::iert-.tion of ti:e o. :x-rst~·~:. 'i'Le 

dangers, of course, in not ericOO.in~ the cipher indic:,,. tor~: ·:1e1·c 

c 1 G<:.l' l;;,' d err.or:s tr8. ted b;;,' you s a!1G t.i !.~G u-1:;0 ':ii th the result th'. t it 

-::::.s decked t1J;;·.t ari.~;t!tin~:· f\~rther i.n t.hc rii::-;J of officicl bnsir;ess 

::ent: over the cipher )l'inter ·--0t<lu 1~,_cve tYese inclicaturs 8!!coc!ecl. 

'l'he ~:rroposition now befo1·;_:- tile ;"'0use is ,th;::i·1.1\,:i·e,·:iriether or not 

one Uolonel ~'ahy...:.n is ·-:!i1linc to :~:.;.ve i!:i.s force tackle a still r::orc 

difficult proble!:~, or r:.t.~er t-.vo )roble!:s; ancl ril1ether or r:.ot I:e is 

,-;illi:n; to _j.ve a dee i.si·:m c,.t once in reg'-!rd to foe 90ssi1Ji:i ty 

of deci.)herir:[;' !T.essa:es _:::il.·e1xtreci in t".70 different '::aysc 

1. t;ipher indic~'.tors to be er-,coded, :md the ci!>her to be used fo:r 

_the body of tbe ?:es sage alone: V.•10 ci11her tapes to be used as in 

for r:£Jr ;ir.: .. c tic e. 

2. Onl;;.· one cipher tape of GTC2t lmcth to be used con.ta:.nir:g a 

running 1rn:_; selected-without rhyme or reason, bod.¥ of the r.ess<.:c.::,"0 

only to be enciphered an<.l l'..ey indicc.tors to be encoded.. 

'l'he opinion of Hiverbank is requested as to whether_o1· i:ot thei deem 

both or eitrer of t!1ese :r.ethods as indeci~)r.er: ble. Lf either or 

both a.re believed deci1)herrJ)le, are ~iOU willing to unuerta.ke ti1e 

decipherment of messages pre:rx:-.red c:.ccoruinc to either or toth schemes? 

I am glad for !TS.ny reasons thut ,'/OU :1av0 deci_pi1ered tr,ese 

messages, 9rep:~red according to our .first sche1re, but, in particul3r 

for one, and trot is that you have now demonstrated to yom· own 

satisfaction tl"l<:l.t too 1ressages were prep;::.red ex;;:.ctly as stated, 

\'lithout trick or artifice beine; introd.uceC., c::.ncl that they really 

did make good ~nglish sense after a.11. I fr-ankl;f confess tr.<:.t I 

have deeply resented tre irr:plicat ions rr.ade from time· to tir!'"B and 

some verJ recently, that I was rescrti1~ to r..etty trickery in preparing your messa:6es, and not _fllayi~ the i:;arre. I trust ~will be 

restored to good stand.ins in your estimation us a result of this 

work. 

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·REF ID:A4148864- ______ ... :_; --

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U1rnn arri v<il of the .iillgli s."ri clec i_pherrr.ent, I sfill.11 take the 

matter, officially, to the t;hlef :Jignal Officer of the .Army with a 

view to !iavi~ recognition accorded Hiverbar:.i·: for all it ras done. 

I do r~ot see hQl.'l t }e government cun ever rei:ay Colone 1 lc'abyan for 

wha.t he has done in tackli~ problems such as these. 

I have a str-c:.n::;;e hunch that sone of Senator r'alls infornation 

about Garranza probably passed thro'l{ih .nivr:rbank. Am 1 a good guesser'l 

Best regar9s, as ever, 

( 

f "f:L-r ,/ ~ ~.,,.-y-;:f, ¥'--~ / (/[,,,<A....~-<.-<./(.·' 

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P. s. Hope you received the tYJO vaouum t-ubes mai le,d the day before '.J..1 la nks gi v :ing •