on "Briet ot felegrau or Departaent ot state• 

Colonel 

l Corderman 1. The probla u to whether the •v.v •hould t'unliah a •waaey ot State De-

- pa.rtacmt despatches to the Briti•h 1a one 

'lihich cannot be positively ansnred bJ' thi• 

o1'tioe. Jlo need oan be eeen ror t'Urai•hing u .iibi• Wol'll&ticm. howwer. it 19 poaaible . :\~~~. l.• a._ya:U,_d i:"t1aaon .. 

•· 1'he state .Department 18 using 

orJPtographio •1atna w!l.th a raao..'1Abl• 

4eg:ree ot aeourl V• Jloa I; aessagea handled 

·on the W..shington-London oiroul t are aryp-

-tographed in a ayatm which ia highly ••-

oure from cryptanalytic attack. lloat other 

State Department holders uae oryptographi• 

systems whioh are reaso~bly seoure although not ot the order or the London-lfa•h- 1~gton circuit. The general quality ot the -· 8tato l>e&l&.rtr~ont .syatams baa improved l•-

lilAWlur&bly •inc• the beginning or the -.r. 

All State Departaent in1tallatioll.8 in the 

alas1 ot embassies. lega.tiona. plua •oa• 

councils hold strip or maohine •Y.t•• for 

handling aeoret tr&ttic. Further, all ••- oret trattio is 'handled in a machine or · 

•trip •)-.tem. 

I. It 18 entirely true that paraphrasea o~ aessace• would be of gre&\ Ta• 

luo iii br~ng 1nto a. oryptog:raphio •Y•- - "-• and thia oase 1e no e:zceptioa. It 19 

._tirely p~s~1ble that given autticient -- ·•or1b• {which these paraphrase• ooald well. 

be), the daily keys tor the generally held 

atr1p a7at.. oould be reoovered. It ia 

---aot belieTed the syat• uaed on the London 

•lliuhingtcm oirouit ooulcl be broba 017p.-

tualytio~lly 1.n. thia .-....r. or coune. 

IUQ' ot the eyat•s are au•oeptable to 

peysioal ompromiee. : 

4. 'aauning it 1s ' desirable that the 

Briti•h be furnished the 1nto:rmati~ la 

our State Department ;despatohea. there 

, . ~ , .. . 1hould be no great oc~noern OYer the ••-

1 ~~ SEE~t:·.at_·-._ 

~.iw..~'*_ ==:_J"- :._:.;.~; ;: efA j f• 

eclassified and approved for 

elease by NSA on 04-17-2014 

ursuantto E .0. 13526 

_.,,"" ... ·-· ...c.. ... i i' 

.J. ..,- ,--.... T O' 

= I I '= 
. ,_ 

1 

(Coat 1d) 

ONI "Brief of Telegrams of De,.ia!"tment of State• 

(Cont'd) 

ourit)' o!' the cryptographic 1yateu with 

rospect to the Briti•h providir1g these 

1ye'blae ca:n btl e~ed 1-tediately should 

it be decided to no longer publi•h the 

d88p&tch.e8. The systems in uae in th• 

Sta'9 Deparlaent oould be ••ily ohanged 

proTi.dini; sutf1o1ent time ware g;iven for 

the distribution 0:f' :rftlw keys. 

6. b a reo~ended solution to the 

proble!tt• the fora of the daily 1\1111!11&.r)" 

might be changed to a· dig-est in which all 

:retereaoes to dates. m~ssage numbers. eta •• 

would be elbtinated. .A.11 aeuages should 

bto thoroughly l*J"&phrased with all qi.otea 

re!'.H1Yed. !;ii W1Juld p-ea.tly incl" ... 161 tbe 

d.it.t'ioulty of UBing i*raphrase• .. a •orib• 

and would ofter a mid~le oour1e oau~ing 

the lea8t amount or .. baJT&aaaent to thoae 

cou.rned. 

.lttaohed.1 

#1 -..0 tor Col Clarke 

dtd 15 June 19.u 

fl Me1P.o tor Col Clarke 

Dtd 11 lla7 lMS 

•/bola • .A. & B 

#3 !uok Slip tra Col Clara 

f.f. Buok Slip ha Col Cordenu. 

Chlrl•• B. Biaer 

Major. Sipal. Corpa 

Cryptographio Braaeh 

19 JuM lHI 

Si&. .)ii.~ .... /J ~. {J::· SEGR~-T 
I. 

::.~ --- -

ME:.MQRA~TDU:M FOR COLONEL CLARKE 

' ' 

June 15, 1943 

Subject: Atached Papers f'rom ComJ•.andar Wenger 

I suggest that Comna.nder ~eger's.memorandum and the accompanying two papers be referred to Colonel Corderman for his opinion. 

The NaV'J's reply strikes me as not responsive to the questions which we raised. I directed Comr.ander Wenger's attention to 

the fact that the British Admiralty Delegation was getting the Navy 

Depar'bn.ent's summary of State Department cables, pointin~ out that 

the sun.T.ary was not devoted to material of purely naval interest, but 

covered in ~eneral ~11 intelligence that was found in the State Department corun.unications 1 and that this vJB.s a very gyestionable way 

of giving s.tate Department information to a foreign organization. 

On the specific question of possible conpro:r:tising of codes., 

I neither said nor had in mind the matter of paraphrasing. It may be 

that our Sta.te Depart:::.ent codes are so secure that they cannot be b'roken evey by one who has kr.owledge of the contents of particular messages. 

To my ~ind, however, it would be foolhardy to make that assumption; and 

if that assumption cannot be made, then the point that I •va.nted to raise 

was whether we were not ma.kine_: it easy for the British to read State 

Department enciphered messages. I s~ould suppose that a crJrptanalyst 

would get off to a pretty good start on reading ciphers if he received 

from day to day even good paraphrases_ of' rr.essages containing specific 

infonnation, naming nanes, giving numbers and containing information 1 that so~eti~es can be identified in terms of specific words. 

It may be thl).t the interests of this country would be best 

served by a complete interchange of oriGina.l messages with the British, 

eve~ to the polnt where they could read our enciphered material any time 

they wanted to. Personally, I do not think that that would be a good 

poJioy, and moreover it is not the policy that the British Govermnent 

pursues to\11&.rd us. ·.=.'hat I think is our valid objection to the Navy's 

course, in relation to the Adr.i.iralty DelegatiQn, is that the Navy Depa.rtnent is pursuing its own private policy in this aatter ~~thout 

consultation with Arlington Hall, (which sustains sQ!:!.e degree of.rep 

sponsibility for the security of State Depart?r.ent cornr:unica.tion.s), and 

that the policy seems, at least to me, to be contrary to the policy 

that is pursued by branches of the Government other than the Navy 

Department. 

' ~-l • In this connection, among the facts that I -wanted to repor't 

to you and Colonel Corderman, which I learned in England, were the 

following: 
!-- ---~-

• 

_, 

=-..:..--~ 

--- ------

Co~nder Denniston, when he gave me the organization uhart 

of this outfit and told ~e the history of-its operations since the last 

war, said that he thought he shm.~id-be perfectly "i'rankwlth--me-and-there- -

for wn.nted to admit that, up to the time when we entered the war, Berke· 

ley Street had an American Section which devoted itR atter.tion to our 

state Departnent communications. He said that when we entered the War, 

Ur. Churcill had personally ordered Berkeley Street to stop WJrking on 

.Ar:l.erican codes, and that the Section had boen dissolved. He says that 

since we entered the war they have r~t attempted to raad any United 

States cO!ll!!:-unications. I ha•e reflected a good deal on this staLern.ent, 

in the light of everythinE that I saw in England and of my own estimate 

of Denniston, and I persor..ally have come to the conclusion that it is 

correct. In other words, I believe that the British are not attempting 

to read our State Department comn.unications. 

Tha Dritish, however, are very realistic people, and depending 

on the course of events will certainly at sO!!le ti~e -- possibly while 

the war is still on -- resume work on United States cOilll"l.un:i.cations. 

There is no doubt whatever in my mind. that our com.munica tions, a very 

substantial part of which pe.ss through London, are received by the 

British censorship along with the com.~unications of all other countries, 

and are being kept on file. The Navy Departrn.ent, therefore, is supplying the British GO'rernra.ent, through the Admiralty Delegat:i:on here, with 

paraphrases of a "substantial portion of our State Department Traffic. 

If and when the British resume work on m1r ciphers. they will have quite 

a file of nessae;es, the general contents of which they will know. Will 

this not be of use to their cr~rpta:ne.lysts? 

The follovri.ng is another bit about past British activities in 

reading our code~ 

The present head of the Beau :ttanor intercept station is Commander Illingworth. Fro..~ wha.t he told me about himself I concluded that 

he had been a cryptanalyst in the Navy until the early of middle 30 1 s, 

when he retired and immediately joined the Foreign Office. In telling 

me about his past activities he said that he used to read the u. s. 

state Deparb:tent ciphers and remarked jokin~ly that it was "lots of 

fun11 • 

A. McC. 

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I 

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