REF ID:A4148Bifi ...... 

tly Li.ear General Sy_uier: ':ie have just received the follo-..r:ilc.t; tele::_:rar;-. of :.5Jth; 

"He rol 6.a. te. Jur lar[;eS t s te.t io:r; sends 2n :=:.ve1°age of thirty to forty 

r.:essa;;es averat;inG forty Y1ords each in onr3 d.s;:;-. StOl'• ::Jo ~ro-...1 cle::iire 

one hu 11d.red .. nessa.:;es, includin3 three actu;;.l ci2.y 1 s \•:ork sent b:' one 

:itation but encilJhered. by one set of Le~c t2L)esoi£ d.o ~rou t~re:fcr '-'11 

rnessa;;es enci

1

;hereU. in sace lrny tc .. pes se:1t b~1 ~~ sta.tionhn 0:!1C C.c\,·, 

\'lhich should ,;ive total of :::ore than one r.und;:ed. :::ess«'2·es?' 

~le feel that thore 0ould be no pur~ose in solvin~ ness~~es in ~ set of 

keys ·:ihich ct'e in use for a ~-·eriod .=;1·es.ter thc:n that ~Je1c.1itte~ i:l c.ct'..<c::. .. Jcvice. 

Our UlL~'..)L''.lc::.U!iE,; c.s ~)ven o;:;· Col. =~2.Ubo1·,~1:e' •;;it;}1 re 1sc.rd. t.o '~he m.:::J.Jer of ,:cf;~.s:::.~::::s 

sent b~r a station ".\'&.S that s. staticn l'lhich sent onl:/ fort:r CH' fift:.- Lessc:.'-'·e" .::.. :lq 

·r:as c:, very i:r.2ctive 01ie. Col. :.:autor_,;ne cited t'.1e ..::':::.ris stc.tioD c...s bcir.:_,· s. ·u'.ls;/ 

ono c.nd that :;:s m8.ny £cs one or t\;o thouss,nc} 1::P,ssa;·es L:i~~1t be sent in 2.. si:r\::)c 

day fro!~! suer. s. st9.tion. J:nis mi:.:.·ht, of cot;_1·se, re~Jre!:~ent the extr~~,e of c:.ctive 

operations, even llurir\:,- war ti.rae. 

0ur ide<-'., for tr.e purpose of obtc: ini·:1z c. i;:ore intimate i.no\':leC~e of the 

possibilities of the situation, would be to h<:.ve ~.resenteC the :.'.ost fs.vJr'-ble cc:.se, 

n8Jllely, that in '.':hich it is !!l'esi..m,ed thc.t the f'.:.dChines c.re be int,· used i:-1 Y1c::.r tir:10, 

'.vhen the traffic is ver:; lieavy. ·::e feel thendono, that our rec1u:::st, as contc:1.ir.od. 

in our telei:;rw11

• \W.S Cl :.10ciest one and \':as moreover, :itrictlJ -:-:ithin tl:e li!·~.its 0£' 

the LJromise of Col. I.:aubor~ne, to tne effect that \'ie co"J.lc.~ have Ei.G i:12:ny r:1e::;sL~cs 

c.rnl 0-s many C/Cl2s 2.s vie should re'-iuest. ]O our uir.cl, if a ver,y c:.ctive st2.tion 

sends oi.;.t one thousand or two thousand r:iessaces ;:;. da;/ "Chen ;c~n ~:.v0ra0c stc.:..tion 

v:ould. surely send out one hundreci. mes sa;::;es c:. de.ya 

:;{o·:;ever, sLc .. ce you have i)resentec't al terne.te propositions ancl since, 

as we have statecl above, there i::ould be no vur9ose in our 1·;orldnc; v:i th the first, 

Vie must accept the sec::md, namely, "all mes s2~es enc i1herec'.. i11 sG:..i:.e ~ce;/ tc..c;es ~,ei--:t 

by all stations in one day." J.'his, as :/ou say, ·,,:ould. i';ive 2 .. total of :-nore tr_s.n 

one hundred. messages, antl we v:ill therefore loo~-; for about one hundred fifty cessc.;:_ies 

of representative lenBth and text. 

~lec:;ardless of this test, \'."8 should. li1rn to have Col. ::&.ubort;ne 1 s 

opinion on the theoretical aspects of the solution, as eh~cidated in A.ddendur:: I 

to the orie;inal explanation. .DesL)ite tr~e fact that no actmd solutions of test 

problems .,·:ere i;Jresented to hirr., Col. :.IE:.~lborc, .. ne had no hes i ta.ncy '::hc;.tove1' in adLlittine that the method of solution as outlined to him in confBrence ~as Qerfectly 

feasible. The explP,.nation contai1~e(L in the s.fo.cer::-,entionecl addenclt1Jn s}10\'iS that tl'ce 

principles of solution which ap"tJlied to that method of usi.ng the 1.1achine which he 

cla~ned was not the method used by the Jii~al Corps also applied to the method as 

outlined. in his pencil memorandum. lf Col. ~12.ubor.::--i:.e C.oes no;; a0rec in t!-1is, it 

woul6. see:.t ir.ci'l!:'.bent on him to show why they tlo not appl~r. ~his, to our :;iind, 

@'pp roved for Release by NSA on 11-18-2014 pursuantto E .0. 1352a 
REF ID:A414BB'ti 

-2-

~ould be the real spirit of co-operation, rathor than a challenge to prove our 

clc.ii:is by solving a series of 1:,essages, ·;.'hich may involve a consider&ble expenditure of t~~8, labor and =oney. 

Ho~evsr, since your idea is thdt & ~ractical de=onstration is ~ore 

v&lm:.ble tho.n a theoretico.l uiscussion in ttis case, \·:e s!1c:.ll endeavor to do 

OUt' best ·:;i t}1 the test to be subrni tted. 

Sir_cerel;; JOUrs,