1: 

I 

j 

t 

l 

f. 

1 · 

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II 

REF ID:A44766 

Liber~7 Beum&er l!il, J'JJI 

-·A re Iii Giving Awa) 

u1 @ipher .€xpert • s View of the JrCethods Used by the qo't•ernment 

in Its 'Diplomatic Go1Tespo11dence 

By 

HERBERTO. YARDLEY 

(R11adin1 eim1: IS min11t111 10 ••o'IUl•.) 

O:SE of niy deep regrets at the reception of my book, 

The American Black Chamber, is that it has been 

accepted as a story of romance, intrigue, and ingenuity in the tracking down of spies through secret inks 

and ciphers, and the uncovering of foreign machinations 

through the decipherment of diplomatic meas&IJes, instead of as an expoai of America's defenaeleas position in 

the field of cryptography. 

I bad hoped to bring home to my government and to the 

public the dangerous position that America holds by 

abolishing the Black Chamber and at the same time re- taining antiquated codes to carry our diplomatic se- crets. All great powers have their Black Chamber \Vhere 

the best cipher brains in the world puzzle out our rodes. 

I bad begun to believe that no one cared to read between 

the lines of my book, \vhen I received an offer from a national magazine, suggeating that I write an article describing in detail what sort of codes and ciphers our government should adopt. In this manner it was felt that 

the Depa1·tment of State might be stung from its lethargy and indifference. In almost the same mail I received a letter from one of America's leaders. 

" Ia it realJy true," he wrote, " that we no longer intercept the telegrams of foreign governments and decipher them? Is it also true that the State Department still uses the t.rpe of codes that do not safeguard our secrets from 

foreign cryptographers? " 

My answer was ,·ery short. "Yes," I replied. "Both 

statements are unfortunately true." 

A few days later I received a letter from this'man, asking me to come to see him and begging me to bring some material that he might learn more of the science of cryp- tography. He pledged himself to use his inftuence to force 

the State Department. by indirect means, sooner or later 

to adopt safe means of communication. 

" Since we no longer have a Black Chamber to decipher the secret meaaages of foreign go\•ernmenta," he Wl'ote, 

" it seems criminal to me fo1· the United States to piny into 

the hands of foreign go\·ernments. The least we can do 

is to protect ot1r own communications.'' 

I gathered a few trnewritten brochures on the deciphcl'ment of ,-arious types of codes and ciphers-it was . alwa)·& the practice of the Black Chamber to put down on papel' any ne"· disco\·ery-and caught a train. 

When I was announced, he cleared his desk, told his 

secrc-tary that he waR not to be disturbed, and, tu1·ning to me. wrinkled his hea,-y eyebrow,., " I want Y(lll to explain one thing to me," lie demanded. 

"You worked in the cocle room of the D(·pnl'tment of 

State as a young teleirrapber and code clerk for a number 

of yc:ir,.:. You dem1mstruted, b)· actuall)' deciphering their 

code:!'. th:1t they were unl'afe. . " :r 011 were later employed b3· them on secret p:iy roll to 

mi.ercert and decipher the message~ of forei.i,:11 go,·ernment,.:. You handed the Dep.·u·tment of State O\'er ape- riod o! tweh·e )·ears some fort)·-fh·e thou11nnd ueciphered 

me!lsa1te!'. ~.ow tell me this: Wh~·. in God's name, if you ·tell them their codes are antiquated. don't they demand 

thut yr,u modernize them? " 

I leaned back in my chair and smiled. " Perhaps the 

Department has ordered thumbs down since I wrote The 

Ame1•ican Black Chamber." 

" Thumbs down! " he e.waimed. "What ha,·e personalities ttt do with national danger? If I had been Secretary of State aud read your statement that our codes were unsafe, after ha\'ing employed you secretlr to soh·e 

foreign codes, I would have demanded your presence· in 

Washington to pro,·e your statement.'' 

I had not expected such an ardent supporter. " It's 

obvious," I said, 11 thst·you have nner worked for the ~ 

B<ll-emment." 

He sat frowning. " Why don't you "'rite the Secretary 

of State a letter oJfering to turn over to him '"'ithout hope of remuneration the type of cipher you describe in your book-an instantaneous and indecipherable cipher? " 

" A letter wouldn't do any good," I said. 11 Did you ever write the Department? " · 

THEN I told him of the letter I had receh·ed f.rom a ~t!i>1Jal~zine.pdJ:hatI ~nedt.Q)vr.ite;&piece!l( 

exp"'"'tu.n for ;.t. TJ'1' nd\·i~1"*t'f in J1~:- .. .:e..;- ~' mr :0Jt·f'rnm~?:t that 1 should tfrst offer to turn ol·er t.o the Department a memorandum of what form of secret communication they should use, with the provision that I be assured that the 

memorandum would be acted upon and not merely filed. 

This I felt a waste of time and effort, and told him so. But he WBB so optimistic about the Department's reception of my letter, and so distressed at the idea of our secrets 

being read by other governments, that I agreed to follo\v 

his ad,·ice. · He ga\"e me a stenographer. A while later I handed 

him the propoae_d letter, which read: . 

Pit:tm·111 b11 

ROBERT A. 

CAMERON 

. -...... -··~·''tj .. .. 

r.~ f 

'"\ 

' ./ 

/ 

.:-, tC ..... ~ .. . 

• .,. •• :;;. .. ••• t ·= ... ·. ,•. •4~ 

•'. . ··..: 

, ....... ,.. rt. Hll 

;S,;, 1.1.'f AMT ul' ::T,fr,, 

:'T.t.tl: lh P.llC'TMt • ..-r, 

WA.•llllu.tl!S, lJ. C', . 

~II 1•1"-lll ~la: 

In ~IU•l~ler XIX o( DI)' book, Th 

bo.r. a ""l'Y of •Inch I am ""nding: )'• 

ha•"l• de,...r1bo.-d a eun•'t!r~atioa I had 

ol the Dt.·par1ment when he uk,'d 

l>e1111rtmc.-nt'11 code me$Sllgea to dece 

wer• ~oluble. The conversation •" 

State llepartment had received I 

110•·1:rnmo!nt .was interceptins an1 

diplomatie meaapL 

It is not neceua17 for me to d 

ha•'t! in mt book the. variou pci 

Sallee it to RJ that I advised 10 

that ;rour eodes were soluble bJ 

tocraphen; that it was not onl 

tbe agents of foreign pYemmen1 

'confidential • eode and cipher n 1agea, but that the1 were undcn; 

edly doins so; that the methoda 

the Department for eneiphermell.t w 

slow and cumhenome. heinc no l'I 

;""'~~·~:: .., .• . ¥.Ji!f,P!PS:i4S: PS'°!" P\ ' I 4 *• "'· ,OfU • "''~PF .4,P"~-..,...,..,..-•• -~M-..,............l·: ..... """I'· .. - ..... ~ ............... ...,....~ • 

. .. .· ~ . 

·~ 
REF ID:A44766 

December J\I, J•1Jl I.a Lerty. 4 

AwaJOur 

1Y the qovenmzent 

e 

EY 

i-ed thumbs down since I w1-ote The . ber." 

he exclaimed. " What ha\·e person· 

ional danger? If I had been Sec:re-

..! your atatement that our codes were g employed )'OU aecretly to sol!e 

id ha\-e demanded your p1'esence 1n 

'\"our statement." 

j such an ardent supporter. " It's ·· t ;vou have ne\"e1· worked tor the { 

" \Vhy don't vou write the Secretory !ng to tum o\·er to him without hope ,. t)-pe of cipher you describe in your -.us and indecipherable cipher?" do any good," I said. " Did you ever 

~!" t' 

of the letter I had reeeh·ed from a ~~111! l..b!ll I t:!an111!(l t,o w~·ite !! piece. of I ~•""~kr-jn'ilt'ic:e'to-mygovi!tnment 

_er to tum O\'l!r to the Department a f · t form of secret communication they pro\•ision that I be assured that the · be acted upon and not merely filed. r ~ of time and effort, and told him so. · s:.tic about the Department's rece1>tion 

diatresaed at the idea of our aecrets 

go-..-emmenta, that I a,irreed to follow 

ographer. A while later I handed .• er, which read: 

THC HONORABLE HESRY L. STIMSON, 

SECRETARY OF STATE, 

STATt; DEl"ARTMENT, 

WASHINGTON, D. C. 

MY DEAR SIR: 

JULY 11, 1931. 

In Chapter XIX of my book, The American Black Chamber, a eop)' of whieh I am sending )"OU under separate cover, I 

have described a conversation I had with a responsible official 

of the Department "'hen he Hked me to anal:rze the State 

Department'• code menages to determine whether or not thef 

were aoluble. The eonvenation 1rew from the faet that the 

State Department had received information that &11other 

pvernment wu Intercepting and readiq our 

improvement over tho11e emplored in the sixteenth century. 

I was asked at that time.whether It was possible to d.,vi•• a s)'ltem of encipherment which -uld render c.11r measag.,1 

indecipherable by even the moat expert cryptographer• of 

other governmentL I assured yo11r official then that it was 

posslble to do this, but that it could only be done bJ a consideration of the faet that no eQd11 or ciplter iB irnpr1111nablr. to 

attat:k H11les11 it i• iuolrtllhi b11 tM i11H1ttor l&imnl/. 

All existing codes now emplored are broken in the end 

by the faet that the inventor attempt.a to conceal repetitions. 

The onl:r indecipherable means of communication ls one in 

which there are no repetition• to conceal. The adoption of 

(COJfTIJIUllD 0111 lllDT P.&CBJ 

diplomatic meA&p1. ~7). It i1 not neeesBBr:V for me to detail here a1 I ~- ;.: '• • have in m:r book the variou• points disc:u••ed. (.!. x~ . . .. Sullk:e it to aar that I advised )"Ollr oftleial then ., , . ·;... . 

that your codes were soluble b:r •killed cryp- \ !$' · ' 

tographen; that it -• not onl:v poaible for · · , ' 

the agents of foreign pvemments to read our ;i.· ~· •• ·~ 

"d SENT Uae tJOda IOOf'4 :J mecmiag tea Million 

tfoll&n. Two letten toms 

cra-poasc!, wl&ich cl&a:noetl 

it isto tAe word 'lflft1liag 

"confidential code and cipher mes- ~ i"'o 

uces, but that ther were undoubt- ([' ~ ·" .....__. · edlJ doing BO; that the method• of •"' · • ' . ..._,, 

the Department for eneiphennent were • \;<.: )- 1 : -~ aJow and cumbersome, being no great ' : ,,...-, , · .' ! ~ • ....... ~ ' .... 

~ . · . ..~ ~'-"'"' «I'\ ~~ .. (... . ,. ~~-~ .•.. ! ~v·· .·.. ..~~~-. 

~~It'.~ ... -. q~_:J. . )~.~.:.. \.t. Y!J<.J ,,.,. ~~~-- ~ :. ~ :>~(\.~ ' ~ "' ·~ ,~·.:. ~. ·. -~. , . - .{ ·•. ..... ·:.;._· . '£' I.'·\ 

{ ., ··~ .. ~' .J ..... • ~··--:.,-.·· .. \,.,·,, ..... "'-..... 

~....... . . :.:. •:--::; li ,-~ ~ ~.: ;/·,, ,_. . ~ ~)' ~ ., ··-:.1 :.~:.~·~·-~~.. . \. . .~.· ·l"' -· 

---=i=, . l· . l / . . . ~- .... . : ;" 'i\ ~·· . ,. :· .. ¥-- .c ·· ·,~ . f ·1._.-:·: i" ;~;;: . . ... .I ... r.: ~ .. .· -J.! ,~, '·\ :. . . ,., . .,.,.,. ···~ 

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-7.l< -~: · ... ..:.··:.. /~ / :-." .-~. "'\ ~~ .. '"( "'.: .. ('. "fl·~: . ';"\ ....... ) ... ·- ·1:· .. I ": , .... __ . - 1 ~. l•h" • • • • f. ~·-' . . 

elnea t11illioa tlollanl" . 

.;;.z· · 11. .. _;-:;.· -' ~-; 'L' :· ·., '\ . · "•;.-. __ : ·•. · · '--'.,.# ... -:-: .,..,, .. lo. ":.,.''° I!: / "! rlj.fl4 -t°•'" f ~ ~ : ,. o o' •' '...;.,:;•,:,.. • ., "',\ 1..-. '"I 

-=:ti---- ~ ·.~· <1• ' '\ • ,, • 1· ~-- . ;,.:_ . ."'\'---·?"-· . " ·.~ .. ,.;.· r .- -..... .• 

,;..-.-....... ~ ... \! • • o "••~-' 1•• '··~·;.;· .. ~ ·. · .. : 11 ,' ,' • ... •I ':;~( • / 

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~ ... ··-~·. .... / '·." ..... ~ 

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~i-.... ' 

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./·': ' ~'":' .1\ '1 :\ 

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. ~·-, //"' .. d'-····...,,-··, ./// .. ... .. ·.~ ... . 

, .~:·., . • ... ~\ ~-=-=::_\; . ·. ;·?·-;t.~~. l ··· r ·.1 :'I' ,_1 ~, ~ S~-::::::..;;~~r-:.~-·.r--:\1 ,:;:. ~-<'·. . · .. ~ ....... f 

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-· ., : ... +:---:;..: ... : ._:...,...-...;..:. .... ~-!':. .• .• . --·. ~ ... ,; ~- • -~:\ . . :·; .. , ~ • " •· ' 

. : .. ,,..- , _,. .. r \o / o . ·- t-z·~ --- '""' . "'-~~~ ~.\." \ ..... . : , ... -·.· " ... 'l~, ·:. .. o ·::..•11 .. .. I J -~ : .. -:r,: . . '\ -~. ---::::-. '=" ·~ .:~ . il . !:~.... . .. .-. . ..~ ·. ~':; .: ~· . . .J P--'~ . /. ----. -- ,,.... ~ - ........... . -~ ,. .. ' .. .. ·-- . . . -........ .. . . . ·~ .. '·· ., . . ... . ...~ . . . .. . .• •• _,. ""~111 

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, "'f(J' ..... "'" .. ,..,. .... ~.y.,,..__,.~.- r• .... 'lllt-'w ~;s..,.,.~ ... ,, 1 ~ ~· ·~:1.......-to ........ ..:'Wr....,.•h ... -.·~ijljar-

. ~:·ll!f''l~~ -·-Pll'l'l--'."J"""!' ..... ..,.. ...... ..,.._~"""!'""':':""----~-:"!"'!!'l"' .......... .__'l:!',1~.""---:i"l!.1111'!1!.111!1'.ll!.lll~IJ'l'll'll. '!!". -·"'""""~"'!. ... . '<}'' . 
REF ID:A44766 

JU ~1uar1,_--~~~~~~---,,._~~~~~ ...................... ,. ........................ .. 

r 

, . 

\ 

.• 

.• 

1lmi·t11een a"d l1l'4rd •.fa lut o/ 1'11t'flioda of sceret com.. 1111n.irafiot1, bJCt the mo11t dtlight/vl ot1e i1 c111nnmnirction 

111."er the tele)'Jl1one b11 the wre o/ AmerieGn alang. 

[ ABE \ll'E Gl\"ll'G AWAY OUR STATE SECllETST] 

Cenlln• .. ,,.. - •I• 

·'uch a c:t>de &y our State Department is prac:tical. It would 

:-r.f1 i:uard our diplomatic messages forevf'r. Jt ran be mado 

l·"•>1hlo for practical use through the emplo)"ment of mac:hin- • 'r ,.., c:i\ e not only indedpherable but also instantaneous c· JnT.,ani..·ation. 

I h:av1• rooe:ently ooen approached by a national maRazine 

''loin.;.: 11n anicle deKribing the nuture.~f such a device. I 

f .,, 1· refll:cr1t to di\·ulll'e this inCurmation, and will continue to 

'·" "'· until I am cr:onvinc:ed that m:r governml!nt has no interest in the matter. If the State Department desires to make 

ita aae of eodea and eiphen insoluble by foreign agenta, to 

improve the aerYiee of tra1mni1aion immeasurably and guarantee forever complete secrecy for confidential mesaapa, ( 

am prepared to turn over tbe neceuar1 information without 

charge or claim of an:r sort. 

But I shall not tum it over to my government until I am sati11fied of its goad faith in the matter, of its intenion to give 

the auggestion a fair and complete consideration; until I am satisfied tbat examination wlU be given by a eompetent com- mittee and that the method wlll be 'adopted should thia com- mittee report favorably. 

If, within a rea9'mable length of time, I am convinced that 

the State Department has no genuine interest in the matter 

I shall feel t:ree to proceed with a publi11hed report of the 

exact nature of this in1tantaneoua, indecipherable metllod of 

commu11ication. 

Moat 1ineerel1 :roars, 

(Siped) Hmamro. YAam.n. 

" I think that statea the eaae," he told me, returning the 

letter. " I lhall be interested in the reply." · I could have told him what the RPIJ would be, having 

observed diplomats at close range for sixteen years. 

I prepared to leave, but he aaked me to sit down. .. I asked you to bring with )"OU some examples of cryptography. You 118)" in your book that during the last few 

yeao cl')-ptography as •B BCie~ ... ,haa, made enormous . 1tride11,. w.hile..t~•te..n!f'artilient.. _.~ indlifet- ,::: · ent to"\\ hal i! gt>.llJji Oil it, t.:'a vu,r:~? 1 b;r: .itO:Jl f:ti!J. C~, 

you give me some examples which I can understand? " 

I smiled, for everyone I talked to seemed to want to 

learn something about ciphers. I unfolded my brletcueand took out aeveral brochures on cryptography. 

'' HEKE Is the famous Playfaircipher," I said, openiq a pamphlet. " This cipher was the olftcial field 

cipher of the British army at the outbreak of the war. In 

this diagram the alphabet is based on the key word 

' \Vaahlngton.' Any word, of course, may be chosen by 

the correspondents for the key. The lettel'll of the key 

word are written in a large square containing twenty-five 

11111aller 1quare1, beginninir in the upper left-hand corner. If any letter recurs in th~ ke)' word it is only used on the 

first occurrence. The remaining letters of the alphabet are now taken to fill op the square, I and J being conaid· 

ered as one Jetter. 

" A measage is first divided into paira .and enciphered 

two letters at a time." I handed him ...-· "'T""'..,.._,._T'""..,, 

the pamphlet, which gh'es the method :wl A IS' H IJ° 

ot encipherment a• follows: f N G · T 0 8 

1. When each text letter ia. in the 1amo C I D E F K 

vertical column, it i1 represented in ripher I I I I 

b1 the letter that is immediately below it; L M P Q R. 

if tho text letter is in t.he bottom column, 

it i11 represent11d b)· the top letter of the U V X y Z 

same colu1nn; thus.: i'loe l'la7f•I• 

WU {text) equal NW (.cipher). ~r,iliorav. 

2. When each text lctt~r is in the same bori::ontal column. it is represented in cirah<'r b)' the Jetter that 

is i-:r1mediately to it.i right; if the text lo::tt!'r ls Ira the column 

to th extreme right, it is repre~ented by the letter to the 

extr1me left in th.e Fame horizontul eo1umn; thus: 

TB (text) equal OS (cipher). 

3. When eu.ch text letter is at. erpraosite c:ornera of a rectangle, ea< la letter is reprer!'nted by th11 lttler in the other oorncr of 

tho rectangle in ~he same he>riz.:intal line with it; thus: 

AF (lext) equal HD (eiphcr) und OAl (text) 

equal GQ (cipher). 

' .. ,.. (4 ••t t,•a. A PI a c J I i "'••.• !'*"'\'~''""'"""·-·"'""-""'.,.... ..... ·~-........... -.. -....-~-,rrt-..,.,_, 

~~:~:·4 

-:~~~<~ ·: ...... ; -· -~ " .. 

4.. When the text 1etten 1 before enciphering; thua: 

Change TT to TX TZ. 

E8BX 

Meuap: " Enem:r retreat 

Divide into digrapha: en 

Cipher: CT 

lll'y friend examined the , " Note the Jack of repetiti 

retreating,' " I said. " E il 

" Before the war this.cipli 

able by the British. Wbili 

cryptography under the ·Br 

Captain Hitchinp, the gn 

tbey still used the PJa,tafi 

turediy at me, and said, • 'I 

but now we can aoh-e it witli 

"AN eiample of.tile •mwj by our alliea and the I 

of the famous Bueriea qlil 

ture of it. 

" The apparatus con.iate c 

movable to any position a twenty-five Jettel'll, and eacJ 

key is the order in which tb 

paratus, which ia 80 COllltrl 

to 1'8\-nl\'I!... . 

My friend wu examining denly hia face lighted up. • 

Uullellilntblr [I am indecip 

does one aend this sentence" 

" By taking any one of th 

top line, cxn·sxDBRZZB 

having first arranged the d 

1110\'1!1 each disk until he h 

row. 

" He now se.;.rches the 

something that 1?'.akea sense.. 

i11dit:bif!rablt'. 

" Commandar.: Bazen"es, I 

that the possibli; cr,mbi • mately two qui:!:illio:.11S [2, 

since each disk 1-.u tweaty-ft ~hi/lro.ble n;;.; ~ Eent. i 

\ •ons as two quil!:.11:,,r.s ra · 

::.1y friend blitl-:f:d his es 

;; Is. \\'hat he s;.ys true?" 

\\ hat he sa;;; alir>1.1: th 

true," I replird. - t. :t it ill 

decip'herable. T::.: .CJ;.clr, c 

of sulutiou. To -:o:t:;:her a · out knowl~dg., c: ?he key, Jlo"e 

fy·four dlft°f:l"l!r.: d~:da; and 

ba..<oed on its fl'!:ri·;~r.:y in the 

turned o\·er ll:e :-,..·.,.::h··fou 

W,hll began to :l!C~ '•II a.cf~ing 

gn·en the letten. Th3 p 

-:. ......... _._,..,.....,.....,~·-;_-.;,._ 
II 

ke 

to 

1rI 

ut 

kat 

;er 

he 

of 

:he 

ng 

to 

ue 

ing 

leld 

In 

ord 

by 

key 

five 

aer. 

the 

1bet 

aid-

·that. 

lumn 

~the 

REF ID:A44766 

Are We Givfrig Away Our Sta.e WU ay 11w&&1 u. : zaa; ii 

. • . ... ,.• / t _, .Ii... .. .. .. ; .. .11'",. ••• ·,,,.~ ,,,. a ~~·I 1·· ,... \. ... ··- ·.0 t.~ -~:--

J 

. ' 

I 

4. \\'hen the text letters are repeated, insert. X, Y, or Z 

before enciphering; thus: 

Change TT to TX TZ, which, enciphered, equal. 

ES BX (cipher). 

Message: "Enemy retreating." . Divide into dicraphs: en em Jr et. re at. in p 

Cipher: CT PD QZ PE PK SG BW TW 

lb' friend examined the cipher for several momenta. 

" ~ote the lack of repetitions in the cipher for• EneJD7 retrea~ng,'" I said. "Eis represented by C. P, and K. •• Before the war this cipher was considered indecipherable by the British. While I was in England studyfag cryptography under the British during the war, I aaked 

Captain Hitchings, the great English cipher genius, if 

they still used the Playfair cipher. He smiled good-naturedly at me, and said, ' That was indecipherable once, 

but now wean aolve it within thirty. minutes.' 

"AN example of the growth of the aclence as developed 

by our allies and the Black Chamber is the solution 

of the famous Bazeriea cylindrical device. Here ia a picture of it. 

.,.':\'be appar,tul! consists of twenty disks. Each disk is 

movable to any jlosition and contains an alphabet of 

twenty-five letten, and each alphabet is different. The 

kel· is the t!l'l!l!J: ir. whiel1 thu dl!!b 1?!1_~!:t.~d in t,,'1e &J>- '"'f°~'tu.so.:"JDClt fa· IO~Diku~wP!imjt the~lf:ilka · to revolve.~' · · : '- · · • ·· · My friend was examining the qlinder intently. Suddenl7 Jris fac:e lighted up. "I see the sentence, Jt1 nia 

ifUUclr.ifraflle [I am indecipherable] on the disks.. How 

does one send this sentence! .. .. By taking any one of tbe other t.imt;r-four l'OWll ot 

letters. The sender 

may take the top line, 

GXYYSXJJBRZZBGB 

~1111111111[ BGSICU, or the bot- ., tom line, MUXRNPC 

RSRRNM:KKUDGFC, 

or any other row. · " Let us assume that 

ne ....._ .._ .,..... the cipher mes1age u . received reads like the 

top line, GXYYSXDBRZZBGBBGSICU. The receiver, 

having first arranged the disks in the order of his key, moves each disk until he hsa tbele twenty letters in one IOW. 

" He now 11e&n:hes the other twenty-four rows for 

101Dethin1r that makes sense. In this case he finds le nia 

ifldicAilfrable. 

"Commandant Bazeries, In deleribing hia cipher, 1ay1 

that the Possible combinations of the disks are apyroxi- mately two quintillions [2,000,000,000,000,000,000J, and, 

1lnce each disk baa twent>··fi\·e letters, the sentence le am 

iruUcliilfrable may be sent in as many dllfere11t combinations as two quintillions raised to the twen,ty-tifth power! • 

lly friend blinked his e)·es at this stupendous figure. 

"Is ""hat he &aJ'S true?" he asked. 

" What he says about the number of comblnationa is 

tne," I replied, .. bat it is not true that the device is inclecip:1t!rable. The Black Chamber de\-eloped a method 

of B(llution. To decipher a me1111age in this system with- . out knowledge of the key•, .M"e set up the meuage on twenty.four diftet"ent disks and ll'ave each lelWr a Humber 

baaed on ita frequency int.he English langua1re. We then 

turned O\"er the twenty-four di1ks to twenty-four clerks 

who began to add on adding machinea the numbers .,,, had 

given tho letten. This ga,·e us twenty-four eharta of 

... .. ___ ~-~ ... , .. \ 

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s.-: -("':.·:.; ~ 1,-.. ··r~ . . ' :~ .,. ; .. ! ,. • • 1,.. .• ~, \ 

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1tatlstics. These charta were then tumed over to twenb·· 

four Cl')'Ptographen. After uperimenting with rh.-11•• 

figures, one of the h1!nty-four cryptograpl-.en \\"uuld find 

the correct aolation." 

M:v friend shook his head doubtfully. 

"There ia nothing mysterious about this," I Pllul'\'d 

him, "and notbipg particularly phenomenal. \\'hl'n 11 

hundred or more men and \\"omen de\"Ole their enlirc t imi' 

and minds to a probl-. • .i, it ia amazing the form11l:l11 thr~· 

wiU discover for the solution of vario1Js l.ypes of codes and 

ciphen." 

ICDllTIXUBD ON NEl:r PAGBI 

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REF ID:A44766 

12 Liberty Dffftm •r Ill. Jr,,ll 

[ ARI! WE GIVING A""Al' Ol:ll STATE SKCJtb"fi:] 

ConUnved frttm pap elHen 

" And the State Department has no one stucffing theae 

problem!!? " he asked. 

" No one." I answered. " The codes they now u11e are eubstantir.llv the same as they were whe11 I was a clerk i:J 

the cocie room.'" 

"I tbink ~omething will develop from )"OU:' letter," he 

said hoprfully. I thought him a bit sanguine, but said nothing. 

A week or so biter I receh-ed an imposi11g envelope from 

the Department of State. This i1I what it contained: 

THE DEPARTMENT OF STATE 

. \V ASRINGTO:f, D. C. 

HERBERT 0. YARDLEY, ESQUIRE, 

WOKTHINGTO!>I, hiDl.\NA. 

S1R: The Department has received your letter of .July eleventh., 

offering ro tum over witllout charge or claim of any sort the information· which in 

1our judgment would improve the code and 

elpher service of the Government and guarantee COlll.plete 11ecreey for confidential 

messages, provided tllat the Department 

will satisfy 1ou of· ita good faith in the 

matter, of ita intention to give the suaea- tion fair and eomplete consideration, and 

that )"OU shall also be 1atisfted that an ex- amination will be given by a competent 

committee and the method )"OU sanest 

adopted should the committee report fa-

'90l'ably. 

The Department would be VCI')' glad to 

receive from y1111 or &nJ811e else any information or suggestions deal.rned to imp'FOVe 

the efticieucy of its eommunication service, 

but auch information and suggelltiona mut 

be to!11clcu·eu. 1111.:or..litlul.l:llly, .and thl! De-

. · ')lai'fiiieiit."iifllh!t~be left free to decide the manner In which aml·tlut es.tea\ ~ wlrich 111ch lnformatlcm 

alld suggestions mQ bit emp10fea.: ll"'yOa are willing:to tender your 1qp1tions on ~e conditiom, the Department will 

lie glad to rectift them and give them 1ueh comlderatioa u In itl judgment ma1 be merited. 

Veey truly )'OUr&, 

For the Aetlns Seeretaey of State: 

(Siped) Wn.a1111 CAD, 

Aaal1tant Secnta17. 

This le, of eoune. what one might expect, but I had had a aecnit hope that it mill'ht be ditferent. One would sup. 

poae from the letter that I was a stranger in the corridors 

of the State Departmenl One would 11ever euspeet that 1 

had been employed there for ten years to turn O\"er to the 

Department the aecreta of the capitals of the world. Nor 

would one even suspeet that I had e\"e!' aeen a code book. 

I very aeriously doubt that the Department desires an Improvement in the communication service, 11& Mr. Carr 

80 diplomatically states; this entirely aaide from unsafe 

eodea. Any improvement requires investigation and 

change; investigation and ehange require thought and 

energy. In any case, let us go do\'\"11 to one of New York'• 

greatest export and import companies and compare their 

eommunication service to that of the Department. 

THE president of the Blank Exporting and Importinr 

Corporation ia a personal friend of mine. I sent in 

word that I had a atrange request to make, and he con- ipented to see me. · 

" l want to talk to one of your code clerks-not the chief 

of the code department, but someone )"OU eon1'1ider just an ordinat7eodeclerk. Iwanttofindouthowmuchheknows.n 

He ~ooked at me doubtfully, but told hie seeretaey to 

send in )Ir. Jones, ""ho pro\·ed to be a thin, long-legged 

youngster. about so\"enteen. He stood nen-ouslt twiating his fingers. 

'' I'm down here to pt some suggestions to improve the 

State Department'• communication aervice," I told him • " But fir11t tell me how long you ha\-e been eneodiDB mea- 8.aJCM and what is your sala?J." 

He looked at hie employer, still uneasy. "I've been 

here aho11t a f.ar," he finall)' said. "My salary iii eiyht· een dol!ar11 a week." .. Eighteen dollar& a week. Do you know much about 

codes and ciphers? " 

" Not much," he replied. 

" Well. if you don't mind, J want to ask )'OU som11 llllt-.i· 

tiona, an~·way. The State Department" begins it .. m1.,. 

sages something like this-" and l v.-rote down on a pa'I: 

No. 648, July 28th. Reference 1our telegram No. 

603, and our telegram Nu. ~2. 

"The telegram itself then begins ln code," I said. " It 

takes the Department two and one-half cable words to send 

these references. How many words would it take vou '? " 

The boy was now at his ease. He studied o\·er the lines a few minutes, then said: 

" I could encode that in one ten-letter word. \Ve first 

encipher our telegram numbers and references in a figure 

table, then convert the figures into ten 

letters which are accepted by the cable 

companies as one chargeable word." 

" That ia a 11aving of two and one-half 

words per cable for moat of the Depart• 

ment's messages,'' I told him. " But let us eall it an a\-erage of two worda. Now 

how long has this corporation been en- coding telegram numbers and references 

In one word? " 

HE waa uncertain, but his employer 

7_'uid, since about 1905, when the new 

ciable regulation" pennittj.ng the u1e of 

t.en arbitrary letten aa one word went 

Into effect. 

I was figuring rapidly. From 1905 to 

1981 la twenty .. ix years. When I was 

with the Department it averaged about 

100. meSBages a day .. taking into consideration the telegrams between other 

poet,a. For a period of twenty-six years this would be 

about 1,000,000 telegrams. Cable rates fluctuate~ but 

conservatively the average coat over tble period would· 

eaaily be ftfty cenq a word. I scareeb' believed ID1 eyes. 

A uvlng of e&00,000! 

"You make eighteen dollars a week?" I said. "Well, 

if you had been with the Department of State since 1906 

and they had followed your system of enciphering references, you would have saved .your government ftve hundred thollllllnd dollars." 

The boy's eyes grew as large aa sauc:en. The Department'• codes are what •e call " one-letter 

differential code&." That is, each code word dHfera from 

another by only one letter. I'll quote a few code worda tO 

illustrate this: 

BABAB 

BAB AC 

BA BAD . BABAF 

Now auppose that BABAB means ei:Mnel encillmi and 

BABAC meana eiolt-inc:A enillmr. The ambassador in 

London during the Armament Conference receh·es a long 

telegram from Washington which dlscussea the cruiaer 

strength and ratio between Engfand and America. In the 

telerram be finds the code word BABAB-si:s:-inch 

cruiaen. But Washington didn't send the code word 

BABAB. Washington sent BABAC-eight-inch cruisers, 

but in tranamiuion across the Atlantic the code word 

became garbled, and upon reaching London read BAB AB. 

So the ambassador rushes over to th'! Foreign Oft\ce and 

talka about six-inehcmisen instead of eiiht-inch cruiaen. 

In order to compare the Department's code words with 

thoee of the business "·orld I asked tlifs eighteen-doJlar-aweek clerk what t:rpe of code worda he u11ed. 

"Two-letter differential,'' he aaid without hesitation. 

" \Vhy 'l " I asked. 

He asked to be excused, and within a few minutes came 

bai:k with a standard rn'ltmercial code book and opened it 

before me· on the desk. These are two linea of the pqe 

he showed me: 

AUWU8-b111 as little u pDBBible. 

AUWYW-b117 u much u paeaible. 

·~flll!ll!!'P "'"·'" ~ :,r-~'F ,' ',"' • ;;cu:;e~ .. Z#ZSPits&tV#i.- .. IWIPji t .. SJO#f4# 1'-"' ... .., ... , ·~·-· ·-· ....,.--.p._ .. _.....,"':!""'!'~;·""'~-<:"',_ ........ ...,......,. __ .,... __ .,.....,_""' 

I I~ I 'I ., 

·. 
REF ID:A44766 - --,--- - -- - -

J'i31 l Dec:e1t1b('r ISi, l!IJI Are W.c Giving A.way Out' State Scertlts? -By Herbert 0. Yardley fa 

i:hL· 

)Out 

ues1'1Cli· 

~ad: 

''It 

1end 

u? ,, 

ines 

ftrst 

iure 

1 ten 

:able 

·half 

:>art• 

1t let 

Now 

1 en· 

~nces 

loyer 

new 

se of 

went 

OS to 

was 

about 

nf.id· 

other 

Id be 

, but 

rould· 

eyea. 

Well, 

1905 

: refbunletter 

from 

~.tO 

·1 

I 

"I'll shuw you wh)' we use a two-letter difl'erential,'' 

he said. " Suppose the sender encodes • buy as little as possible,' and sends AU\\'US. It i11 garbled b)· the cable 

comp311)', and when we receive .the c•>de word it reads 

AUWYS. 'rhe U has f.icen changed to Y. \\"e look Cor 

AUWYS in the code book, but, since each code word diffen from all others by at least t11m letters. we cannot find 

the code word in our code book. This is a warning that an error has been made. u Now suppose the code book had been construcU!d like 

this,'' he continued, and rapidly scribbled the following on a pad: . AUWUS--buy as little a1 pOS1ible. 

AU\VYS-buy as much a1 possible. 

" With such a one-letter-difference· 

code 11.-e would find AUWYS to mean 

was with. the Department at this time this memorandum was handed my superior, Dr. Buck, then Chief of Archives, he is 

not only familiar with the type of codes then in use by the 

Department, but can appreciate the statement in my book 

that sinl:"e then onb· one ehange has been made in the con- struction of the Department's codes. He must alBO be aware of the accuracy of the statement that those upon ""ho~e 

ahouldcrs rests the responsibili~y of nndering our diplomatic 

secrets sa{e from foreign cryptographers have never had any 

experil'nce in the solution of unknown codes and ciphers. 

An"d you must admit th:at unless one is qualified to " soh-e " 

codes one is scarcely qualified to determine the invulnerability of existing or proposed methods of secret communication. 

l shall be ver:v glad to tender uneonclitionally my instantaneous and indecipherable means of com- munication to·a competet1t committee, but 

•buy as much as possible,' althou(Ch our correspondent meant to tell us to bu)" as little as possible. Is that clear! " the 

boy asked me. 

The Int of a series of 

[ must first be advised the names of the 

technical experta who would review mJ 

paemorandum. 

"Yes, it's clear enough, and especially 

interesting that a seventeen-year-old boy in the busillellll world appreciates the importance of a h.·o-letter dift'erential." 

Yardleygrams I feel 1ure :von will agree with me, if 'JOU 

will inve1tigate my histo17, that [am en- titled to the usuranee that my memoran- dum will be reviewed bJ" men who have had 

lone training and n:perienee in the " BOlution " of code• and eiP,hen. and that yon 

will ~ with lllJ' statement that onlJ" an experlenCied 10lver of codes i• competent 

to Jndge the indeeipherabllitJ' of secnt 

- of eommnnication. 

pualee ID dpben wlll 

l thanked him for hia explanations. 

When he left the room his employer said, 

" lf you are really interested in this sort 

of thing I can tell you something about 

code words. From bitter experience we not only insist upon a two-letter"dlft'erappeulll 

Ne1:t Week'• LIBERTY 

ence, but even refuse to use a code 1'ook 

which contains code words which, when adjacent letters are transposed, are in the code book. Such a book once coat this finn·a million dollars. \Ve were bidding- on a project in the Argentine and l cabled that we would in- crease our bid from nine millions to ten. 14 I l!fl~t ·.the code w~rd .mean~q ten . million ..dollars. 

'Vhr.n !t ~:tch"il the .\:-:,"' .. nt111e tli~ l11st two !cttP.n hart 

been transJJOSed, which changed it into the word meailing 

eleven million dollars. Since that time you may be very sure that; we not only use two-letter differentials, but we use code worda that differ from ellCb. other even after 

a.djacent letters have been tl"anspoaed." · 

For yonr lnfOt'lllation I ahonld like to add 

that had the Department of State adopted 

the ueret mean1 of eommunication I 1peak of it would not 

have been necet111117 for the Pre1ident and Secretaey llellon, 

while using the telephone durlnc the moratorium neptiationa, to 1111 lllang, u the papen report, la- an el!ort to keep 

secret from the French Government the nature of their con- ~'t~~ With instantaneous a~ indecipherable me~ of 

co'lnmarii'=atiop...ln. ~ec.t,. Ule-Pi:e111dent...could communicate. 

with hi• M:iniatera without fear of being overheard. 

U J'OU will invatigate the matt.er thonaghl7 I feel that 

JVll will alllO qree with JDe that in this mechanical qe it 

would be dilllealt to defend the Department'• present mean• of eommanication in which code elerb fumble around for 

hoan turnlns the papa of antiquated eodeL 

Yoan ..._,. truly, T (Sicned) HBllBDT 0. Y.ABDUY. 

HERE seemed to me to be no reason for answering the 

State Department's letter. Bad the Department 

seriously wished to impl'O\-e its communication service it 

would ha\•e done ao loDtJ years ago. J SHOULD like to have heard that convenatlon over the 

My friends agreed with me that the matter was closed telepholiel 

80 far as the Department was concerned, but advised l have seen and beard a lot of methods of aecret com.- answering the Department's letter and publishing the munication, but the most delightful one is communication 

correspondence, which mir:ht awaken the Foreign Bela- over the telephone by the use of American alang. 

tfona C.Ommittee to the serious situation. . The incident reminda me of the attitude of a Signal 

The letter I Anally sent follows: Corps colonel in France during the World War. Headquarters had attempted to impreu upon all commanders 

the vital neceuity of the use of codes, for it wu known 

Uiat the Germans intercepted our wireless measaps and 

attempted to read them. One day our own wireleaa intercepting station tumed in a message that wu in plain 

English, but divided into groups of five letters. The 

colonel who sent the messa1re wu ordered to headquarters 

to explain his action. 

Tn HoNORA'BLI: 

Tes SECUTABY OF ST.ATE 

W.uiHllllGTON, D. c. 

Sa: 

JwlflU, INI. 

I have a letter dated July H (A.C) mped by Kr. Carr, 

-A11istant Secretary of State, in answer to my letter of July 

11, oifering the Departn1rnt of State the indreiphcrable and 

instanlanec>us mPaos of communication, without charge or claim of any sort, which l describe in Chapter. XIX of IDJ' 

book, The American Black Chamber. 1'1r. Carr writes, 11 The Department woUld be very glad to receive from :voa or anyone el111 anJ" infurmation or 1uggestion1 de1icnecl1t.o 

Improve the efficiency of Its communication 1e.r~·ice, but suc:b 

information and suggestions muit be tendered uneonditionally, a.nd the Department muat be left free to cleeide the man- ner in which and the extent to which such information and 

Hl'P•lions may be employed. II you a,e willing to tender 

your sugge11tions on thne conditions, the Department will be 

slad to receive them and i:ive them 1uch eonsideration a1 in 

its judgment may be merited." 

1 must confess that l am bewildered b)' this reply. If :r.lr. 

Carr will search tho archives of the Departn1ent he will find 

my memorandum writtl'D bclore the World War while I was a clerk in the Code Room iriving a technical description of my 

method of breaking the Department'• codes. Since Mr. Carr 

" \Vhat do you mean by sending meaaages in this fashion? " his superior oftleer demanded. 

" There ia no neceuity for the use of codes," he replied. .. The Germans are too dumb to read that message." l presume that is the theory of our pvemment. Foreign nations are too dumb either to understand alang .or to decipher oar messages, 10 why bother! 

The whole trend of civilization is tn.iard machinery. So the tnmd In cryptography should be toward maehiner1. 

\'l"hieh means, rapid, accurate, aafe communication. 

With machine eiphen in use, if Secretal"J' Stim110n 

wished to eommunicate with Ambassador Dawes in I.ondon, he could take the elevator to the code room and dictate 

his measage tu the cipher-machine operator, who, while 

writing the meuage on a t-pewriter, would at the samoi 

moment ftash the message ~roas the Atlantic. Should 

Enitlsnd listen In on the wire sh"! would hear nothing l•ut an indecipherable string of letters. 

THB DID 

.-......... p-....-..,. ,.., ................ -_..F ........... ,.,.,,.,,.,....., ..... _,,,.., __ ,..,...._.,..,,,.,,,._...,.,.,_.,,w...,,, .. **'"""'·' ........... Yt..,_,,....... .,.... ... ,,..,a..,w!l!l,&~;s;"'·"""'·'"~'l!!:e""":•=-1•-• '"''"''"'·.""--·"'•'"'''""!'-•"''"'".,::"'c•w•;y."'J1..-1 , ..... - ---