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Declassified and approved for release by NSA on 10-30-2013 pursuantto E .0. 1352a 
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Abatraota trom: "German Naval Co1111un1cation1 Intelligence" Volume IF-210 - 00P7 #' 

Chapter IV, pp 135-161 

WARTIME ACHIEVEMENT ON MAJOR BRITISH SYSTEMS 

One ot the moat striking and 11gn1f1cant tacta &bout the 

German naval communications 1ntell1sence organ~aation vaa ita 

em.ph&aia on low-level codes. An enormous amount ot time and 

eneru vaa devoted to th•• throughout the var, and uauall7 paid 

tor it1elt in term• ot current reading, -it not in terms ot 1ntellisenoe value. High-grade machine a71teu, at the other 

extreme, vere l&rgel7 neglected, or tackled v1th taint hope and 

correapondingl7 aparae r•v•rda. The aoat uncertain but also the 

moat dramatic results vere obtained in the middle ground ... tbat 

ot major Britiah_~on-..,chine a7atema. 

It the average ot success on the minor cod•• is represented grapbicall7 b7 a more or le11 level line, aucceaa on th••• major a7stema will appear in the torm ot a wavering curve - oliJIP1ng 

to a peak in 1940, sinking in 141, reaching a high peak again in 142, dv1nd11ng through earl7 ''+', and dropping out ot aigbt in June of that 7ear. The temporari sags and tinal dovnva:rd 

plunge are d1rectl7 traceable to 1mproveaenta in cipher aecurit7 

introduced bf the Briti1h. 

A• ve have alre&df indicated, available aourcea permit a 

thorough atud7 onl7 ot the British deor11>tion unit, under Tranov. 

A glance at Cb&rt 0 at the end ot Chapter II will ahov that the 

maximua ot var-till• ettort vaa concentrated here. The aoat 111- ~ortant 17ate1111 handled b7 the section vere Naval Code #2 

(Ger ... n cover-name Kunohen), Naval Cipher #4 (Xoeln}, and the 

co•b1ned Anglo-u.s. convo1 cipher (Combined Cipher #3J Frankfurt). 

Succeaa on theae a7at .. a aeema to be conn•cted in a atartlingl7 direct va7 v1th Oer111.n operational 1ucoe11••· Por 'bi• 

reaaon it ••••• worthwhile to attempt a briet narrative h11tor7 

ot var-time achieveaent on th••· Important or7J>t&n&l7tioal 

developments v111 be 41acuaae4 aa the7 occur, but the pr1m&r7 &1• i• to give a rapid general viev ot the triumph• and tailUl'•• 

involved. (For a liat ot British a7atema handled during the 

var, aee Appendix B at the end ot this Chapter.) 

The Outbreak ot War 

At Jlidnight on 26 August 19,9, tin 4&7a betore German 

troops invaded Pol.and, the Br1t1eh introduced tar-reaching 
.. co-Dill ID:A667...,'ff~ We P SEefm'! l1ili'M . f J -U-i -H"-1-' +I -:i. ~ ~~~~--ttrr+r~-

' U (43) 

~~~=: ~~ ;~!~vr::v:!c~~~~s~t the t~;~~f4~l th;:: ~~~:m;e~~ traffic in the two most important-Code 2 and Cipher 4 - vaa 

••ll betore the var. An average or 15 ae11age1 per day vaa 

received 1n the4

tQrmer, and onlJ 15 to 20 percent of the material 

could be read.\ 5J No comparable figures are available tor 

Cipher 4, but the percentage vaa probably lover. 

Ae soon as war broke out, the volwne ot traffic in all ~ysteme inc1.,eased enc1•mously. The section was tempPJ"ar11y Bnowed 

under, not only by sheer quantity or material but also because 

the new reoipherment introduced nn 26 August had4to be solved. 

All work on Cipher 4 was temporarlly abandoned.\'' Code 2, 

however, was being read 35 percent by October 1939. It contained 

a certain amount ot information on the var-t1Me org~n1zat1on ot 

the British Navy and the disposition ot the Fleet. The effects 

of the torpedoing ot the "RoJ&l Oak" in Seapa Flow and ot German 

battleship activity in the Channel area could be tolloved 1n 

the Tratt1c. Some data vae also obtained on Br1t11h convo7 service. 

But Code 2 dealt primarily with patrol vessels. The e1pher 

vaa the chiet aoUl'ce of intol'JIJ&tion on he&VJ' torcea. Work on 

!~!~i!~~!~a~ t~k~~~~1~S:!!: ::..:o~~t:·.:~:·.~:~:~:n~ ;~~=mber~ 5) There bad been a 100 percent increase in volume. The d&11J 

Adm1ralt7 aub ... rin• aurve7a vere tolloved, aa vell aa detail• ot 

British tleet d1apoa1t1on and cooperation vith French naval 

torces. 

It was clear by January of 1940 that the Cipher had tar outstripped the Code in importance. In Jl&rch reading th11 trattic 

permitted the Germt.na to score a major coup, in Vbat vaa pro- b&bl7 decrJPtion•a greatest single strategic contribution to the 

vars "operation Strattord". 

Norva.11 "Operation Stratford• 

In mid-March, 1940, Cipher 4 trattio revealed plans tor an Anglo-French(e~e41t1on against Norva7, under the cover-name 

"Stratford". 40J (For translation ot pertinent paaaagea, aee 

AppendiX D at the end ot the Chapter.) !he Germana se1sed the 

initiative and inT&ded Norva7 on 9 AprilJ the juggeraaut vaa 

1n aotion. 

2 
'i'O P OBCfff!l! Ullf'R/\ 

~~·L-1e Ciph.;;r Wad :..~ead cu;i?1,ently during the campaign. Exact 

data. on British counter ... mea:riJres, auch as lAnding tields and 

·thG arl"ival of' tx•ana:&'.)ol"ts at f..arstad, were known of 1n advance, 

pel'Dl1tting the Germans to ·take appropriate action. 

Whan 7hJrway surrendered early in June t(le decryption unit 

recclved e. wlndi'all ot captured documents. f.47) ~he Noweg1ana had been equipped Yith Cod~ 2 code books, as well aa aeveral 

other liypes, which now became available tor study in lleial1n. 

Apparently no Cipher !t data were captured, but tll\l nev store ot 

rllB.tor:!.al 'Was fully exploited as an aid to l•ea.ding this ciphe~. 

The Horwei.~ian ep1uode we.a u uanna.r ~criod to1,. Tran.ow 1 a seatinn. He was forced to rest on these laurels for scme time. 

By Augu1:11t uew decrJPtion problems bad arisen which accumulated 

steadily durius t~:.e following year. 

The British Improve Their Cipher Methods 

A general cipb@r ebange took plaoe 1n Cipher 4 and Code 2 

on 20 August 1940.l~tl) ~he latter, formerly a 5-place number 

code. now became 1~ ... place, similar to the Cipher. Both ayatems 

were equipped vith 5 .. place 1ndioatox-a. One hundred thouaand ot 

these were divided between them, in a .manner unknown to the 

Germans, so that externallJ the two ayetema were 1nd1•t1ngu1ah- able. At the same time se~rate Cipher 4 keys vere introduced 

tor the following a~eas: 1) North Sea and North Atlant1cJ 2) Mediterranean, Eset Indies, and South Atlantic; 3) East Asia, Austiaalia, and New Zeal.and. There were also ••~&te ke7a with· 

in these a1·eae for different traffic c1rcW.ts. \~~J 

In October the Code was subdivided into 2 a7ateaa, one to 

be used chietl7 tor patrol veasela, J11neaveeper1 and local con- voys~ the other tor per•onnel tiaatt1c and independent• 1n the 

South Atlantic and Indian Ocean. An innovation vaa introduced 

in the l&tter1 apeo1al reoipbering on th10QDe band tor the address - on the other hand for the text.\' J 

Thua in the latter half of 1940 the task ot 'l'ranov•a section became 1noreaa1nglJ' complex and bev11der1ng. '!'he Oode vaa 

neglected in tavor ot the Cipher, vhere succeaa was meagre. 

Then, on 20 Jan.uar7 1941, a aerioua or1a1a aroae. 'l'h• 

Br1t1ah introduced enciphered 1nd1oator groups tor Cipher 4 and 

Code 2 and &1} Oerll&D decipherment of theee s7ate•• stopped 1natantl7.(51 Headquarters vaa deepl7 shaken. 'l'eubner, then 

head ot comaun1cat1ona intelligence, ordered that a directive 
ter. BB8IUl'f UlJ'fM 

be ••nt to all groupa and tlotillaa warning tho that no in· 

formation on the position• and movement• ot Br1t1ah eurtace 

torcea could b• expected tor some time, o~ing to a "baaid' 

cipher change -- aa 7et untathoae4. 

Inten11ve research vaa begun on the nev problem. The 

nature ot the change vaa aoon determined, but the anaount ot 

actual reac!ing done r-ined negligible throughout the summer. 

Aa vaa uaual in auch per1o4a, the leaa important and leas secure a7ateae vere he&v11J exploited. 

on 1 September 1941 the general indicator group book tor 

the Cipher and the Oode changed; it bta.a• extremely d1tf1cult 

to d1aor1m1nate betveen the a71tema.l~~J •our-place !!Slll· 

enoipb;•r•d indicator group• had ben introduced. Thia would 

b&ve .. a. reading eaa1er -- once the trattio vaa d1tterent1&t•d. 

it the Oerana had bad tiae to take advantage ot 1 t. But in 

tvo month• the indicator book changed again,('" the Whole pro• oedure of d1acr1111!Mlt1on bad to be repeated. Oooaaional 

curren.07 in reading the 17ate11S was achieved in the interim. 

however, and again 1n Deoeaber 1941. Scattered 1ntormation vaa 

gleaned on oonvo7 and aerab1p routine•, the 11\!&neuvere ot he&VJ' 

un1ta were tolloved 1porad1oall7, and Admiralt7•• da117 aU1've7a 

ot 081'111.D. submarine positions were read. 

On th• lat ot Januar7, 1942, these aouroea were cut ott 

teapor&r117. Th• Br1t1ah 11aued new code booka tor both a71t.,., and introduced naaeroua one-time CJPhera tor special areaa.\5 Reoonatruot1ng the code booka vaa only a matter ot t1ae1 but the one-t1ae(~~hera vere, a1 T~anov puts it, "invulnerable • ~he 

starting J point and reotp~erment tor individual •••••s•• 

were uaed onl1 once--- never repeated. Increased uae of thia 

"abaolutt17 secure• method hampered deor}'Ption throughout the 

7ear. l56J 

The 01pher, eapec1all7. vaa attected. In addition to the 

one-time pad•• inoreaaJ.ngl7 trequent rectpberaent cb&ngea vere 

introduced. Halt-hearted attempt• to appl7 IBK teohnl~¥'• 

were •4• and tail•dJ reading vae no longer poeaible. t

5a) Jlorale problems beo&lle acute during the aU111er and tall, and bJ Deoember aoet of the 01pher 4 peraonnel bad been ~ana• 

tel'l'ed to other vork.\,91 A chapter which began with •operation Stratford" bad oloaed. 

In another ~etpect. hovever. 1942 vaa a 7ear ot aignal triumph tor German 001111UD1cat1on• 1ntell1genoe. The combined 

4 
'POP SBORB'! \ruffi:A: 

REF 

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ID:A66767 

Anglo-u.s. convo7 cipher va1 broken, r•ad 

l~P with a ~m~H high average ' ot aucoe11, and it• intelligence acted upon bf the German eub-

•r1n• tleet. 

Oo•bln•d Cipher 110. 3: A TriU11pb tor German CI 

Tb• Combined Oipber tor Atlantic convo7a vaa introduced in 

October 1941, before the United States entered the var. On 24 Jan~g!)l942 a special aubaection took over work on tbia trattio. \ It vaa read about 100 percent during Februar7 and 

March, 80 percent trom June to mid-December and again vith6

1oae 

aucceea trom rebruar1 to June 1943, when it vaa replaced.\' lJ 

During th1• entire period Allied •hippins loaaea in th• Atlantic 

b7 U-boat action averaged 360,000 ton• aonthlJJ atter June 1945 

tbe average dropped to 60,000. Undoubted17 other taotora were 

involved, but the inference ••••• olearJ decryption bad made a 

vital contribution to the var. (See the Chart at the end ot 

th1• Chapter.) 

The tiret gap in the long h1sto17 ot euooeae on the Combined 

Cipher came in Api-11 and Ma7 1942. On 1 April indicator groups 

tor all --place n1111ber a71tema changed, and the tvo 5-place 

groupa vhioh(g~~merl7 had d.1•tingu1ahe4 Combined Cipher aeaaagea d11&ppeared. J An enormous amount ot voi-k vaa i-equ1red to 

handle thia ••• ot exterJJ&ll7 aiJli.lar •ter1&1. A general r•-

cipher•nt change on 1 11&7 •3'g,1nd1cator poup change on l June 

added turther compl1o&t1ons.\ J 

But the deorJPtion unit had bettei- luck than it bad expected. The summer and tall vaa a peak period. Bxtenaive uae vaa •4• 

ot IBM card•• ••peci&ll7 atter the introduot1o~ 1n August ot 

separate rec1pher1ng tor the addreaa and text.l 1 4 J Thia bad 

alread7 taken place in Code 2 and Cipher 4. No aerioua d.1.tt1cult1•• were involved here. aa long aa the ke7a remained in to:roe 

tor a month. Later 1n the 7ear th•J began to change aem1-

aonthl7 and readingaloved dovn. 

The second major breakdown 1n Gel'llan aucoeaa with th• Co•-

bined Cipher came in December 1942. On the 15th ot that aonth 

the Brit1ah re1ntro4ggtd enciphered 1nd1oato:r g:roupa tor the 

three 11&1n 17ateaa.l' 5J Code 2 and Cipher 4 ve:re being read 

al.aoat ou:rrentl7 prior to the change. Nov a severe drop occur-

~=:ter~:.~i~~;r:::r d::;,;{f::~Tg6) 00:!n;~h::::id:~o;v~{!:: ~d the Br1t1ah section. Kev working methods vere tol'JIUlated and 

5 
mgp HeBB! ~ coPT ID:A667r~~ 1£Rff 

1ntroduoed.C67) The Combined Cipher atatt vaa doubled b7 the 

addition ot toraer Cipher 4 peraonnel. Hevertheleaa it vaa 

clear, '!r&nov re•rka, "th&t under •x1at1ng c1rcumat&Jlo•T the 

toraer peak ot 4eorJPt1on aucceaa voul4 never recur."\Ot:S 

It vaa eat1mate4, that henceforth current reading vould be ill· 

po1aibl• until at leaat a1x 110nth1 atter a code book change. 

Aa ve have indicated, aome reading vae achieved on the 

Oombine4 Cipher in the spring ot 1943. Thia vaa due in part t~ the tact .that the code book remained 1n torce longer than 

uaual. On 1 Karch the Code 2 book ebanged, but the Ooabined 

Cipher continued aa betore. Tranov round this "aatounding".(69) He b&sarded tvo reaaona tor what seemed to h1Dl groaa negligence 

on the part or the Britiah: l) the Coab1ned Cipher, though oerta1nl7 more important th&n either Code 2 or Cipher 4, vaa uaed 

le1a extena1vel7, and 2) out ot about 2500 4-part number ... - aagea ~r da7, it vould be extremely difficult to separate the 

150 - 180 aeaaagea sent in the Combined Cipher. Aotuall7 this 

teat vaa acco•pliahed by IBM techniques, and the U·bo&t could 

again be supplied vith data on convo7 aovementa in the H&lit&x 

and Gibraltar areaa.lTOJ The Combined Cipher vaa vithdravn on 

10 June 194,, and replaoed b7 Naval Oipber 15. 'l'h1a nev combined a7atem vaa never read by the Oer11&na.-{71) Their period or 

triumph ended abruptl7. 

'l'he Decline 

Prom June 194' until Oerman7•a aUJ'render in Jla7 19•5, the 

ator7 ot the Br1t1ah decl'Jl>tion unit 11 one ot truatration and 

tailure. The vheela continued to revolve, chi•tly on their 

ovn moaentum, but the production line w.a almoat bare. 

The tvo ti.n&l and conclueiv• improvement• in the m&1n Br1t11h 

a7atema occurred in Deceaber 1943 and January 1944. One vaa the 

introduction ot a atenoil aubtractor .. kin' poaa1ble & 4&117 

change ot ke7 (on 1/12/4' tor Code 2 and 1 1744 tor Cipher 5). 'l'he other vaa the adoption 1n Januarr 44 ot a regular aix month 

code book change. Pormerl7 the reolpheraent ke7a bad changed 

• ever7 7, 10 or 15 da7e, and the code book• every 14 to 18 months. 

!he whole atatua of decrJPt1on vaa altered aa a reeult ot 

th••• developments. Tranov eumed it up aa tollovar "Reacling the a7atema tor operational value v111 no longer be poaaibl•) 

except in oaaea vhere the current oo4e boot 11 captured."\71 

In that event, snlutinn nf the daily key w~uld be possible 

6 
i'0P SBOflET BilfRA 

Tranov managed to retain a atatt to ••et the poaaible contingenc7, though aoae voicea vere ra11ed in protest. Oerman7•a 

m111t&l'J' situation vaa deaperate. Th• poaa1b111ty of capturing en9117 doouaenta bee&• more and more remote, and it •••••d un11kelJ that d•cl'J'Ption vould ever~ again make •nr vital contr1· 

bution to the var. Thi• pe1a1Jl118lll~vaa tull7 just1t1ed b7 the 

event. 

At the end of 194' or earl1 1n 1944 (the exact date 1e uncertain), and exhortation to all naval RI personnel appea~ed, (T2

) vh1oh ••••• 1Jnpl1c1t17 to accept the ta11Ul'e ot crJPt&n&l7a1a. 

It auggeats an alternat1ve1 the development or traffic ana17a1a. 

Thi• branch or comnrun1cat1on1 had been neglected to a certain 

degree in tavor ot crntanalyaia. A higher standard ot perto:rmanoe vaa nov required.. Trattic anal7a1a, it 1• stated here, could not equal decrJPtion 1n 11111t&l'J' value, but since the 

latter'• taak had beco .. ao ditticult, the fol'Jler would be forced 

to •••ua• greater burdens. · 

A general report on the etatua ot naval 01'Jptanal7a1a, Vl'itten 1n March 19451 contains the following aucoinct ata.tementa 

"The main enemr e7atema - British, American and Russian - have been ao much illproved v1th1n tbe laat tvo 7 .. r• 

that their reo1pheraenta are either ooapletel7 aeoure 

or can be aolved onl7 with an enormous nuaber ot person- nel and a •xiaull aaount ot d.ifticult'J. "\7,J 

ActuallJ, currentlJ readable trattic vae bJ then 11Jll1ted almost 

excluaively to British coaatal and tactical ayatema, and the 

Merchant Kavy Code. 

The statement quoted above expreaaea a tact. It alao 1•-

p11ea an attitude. There could be no question ot recoYBring lost ground; the game vaa up. Thie tone had become 1ncreaa1ngly 

apparent in the d•cl'J'Ption reports of the tvo preceding yeara. It gave the oco•a!onal pep talk• and aaeuranc•• or rinal auco••• 

a pecu11arl7 hollow ring. . 

7 
ID : A6 6 7 6 ~::'rr::-. ~. : r i I 1 -t 1 • 

! ' r : ' ·: I~ 

·1 I ' I~ i I: I: J .. I: IJ I._-:;!,; kl 

A NOTE 01' AMERICAN SYS'l'BJIS 

Tb• ma1n intention ot the preceding pagee waa to exploit available soUl'cee tor the story ot German achievement on r.jor Allied 17at•••· Aa a reault ot tb1a empbaaia ve have neg ect•d 

tho•• areaa ot act1v1t~ which were ecant117 documented or wh.1ch 

led to aeagre auco•••· Ge1'tn&n attacka on American ayatema tall 

into one or both ot theee categories. However, a word should 

be said on the aubject. 

All combined ciphers ve~e handled br the British seotionJ 

hence Gern.n study or the Combined Cipher Machine (COM) may be 

tolloved in the dec:ztyption reports. In April 1944 the appearance or a new tJP8 or machine trattio waa noted. It vaa deaoribed(,.)r1 ve-plaoe letter tratt1o with a pronounceable 1nd1~ 

cator. During the 1nveat1gat1on vhich proceeded throughout the aUllB8r, a table ot theae initial il)dioatora vaa compiled to rao111tate recognizins the tratt1c.\75J In October seven 

meaaagea v1th identical t1rst and second 1nd1oator groups were 

d11co.eredJ it vaa deduced that the system involved nonreciprocal eubetitution alphabets and vas baaed on plain text.C76) Reaearch on the CCX ceaaed on '1 J&n\a.17' 1945. 

The N&VJ" Bagel1n and the atr1p-o1pher DUPYH were handled· 

in the American section. We have no dec1'7Ption report• trom 

thia aeotionJ according ~o Sohl.\l&e, Vb.o beaded it trom J&n~l'J' 

or F•br\J&l"J' 1944. all records were destroyed betore the aurrender. l7BJ Our only aourc·e or 1ntormat1on is the teat1mon7 or 

various P/W•e which 1a in •nr 1natancea contl1ct1ng and obscure. Apparently no •ore than tvo or three d&ya or tratt1c in 

the N&VJ Hagelin e71tem were read, though one I-report atates 

that it was solved except tor a method or determining toe true 

aetting1. which was aubsequentl7 learned from the Army.l79) 

The Japanese Navy at one time gave & ••t ot DUPm atr1.pa and aettinga to the Ger9n1. enabling them to read th• tr&rr1c 

until th• ke7e vent out o~ torce. It is stated tbat no r .. 1 

1ntell1genoe vaa g&1ne4,'6 I but the Germana vere thua given 

an 1na1ght into atri»a•fthoda. Neverth•l•••• no other •trip a7atema vere aolved.l lJ 

l'apt. Otto von Baumb&oh. chief of the Baval Intelligence ott1ce, and 1n general a great adairer ot the work ot RI, atated tb&t no 1ntoraat1on ot an~ ~1ue vaa gleaned troa the 

atud7 ot Aaer1can aaval •r•t•••·' ~J . . 

8 
~ ~[ ID:A66767 tOPY ' 

UP 8B0RJ!'.f ~ 

CO?lCLtrSIOM 

We have diacuaaed German pre-var and var-time deer7pt1on activity in so tar as ve know it ehietl7 in terms ot outward 

achievements. In order to •••••• the reason• tor those achieve-

••nta, and tor the ta11urea vh1ch accompanied and tinall7 outweighed them, we muat look tor a momeDt into the inner vork1nga 

ot the org&n1eat1on. 

Thorougbneas, ert1c1enc7, technical skill and ingenuity 

were all preaent in a very high degree. Theae tactore encouraged the development ot apec1al1zat1on, or caretully tormulated and 

executed pattern• ot work. When applied exclua1vely to lovlevel systems, aa in the pre-war yeara, the7 brought almoat 

certain revarda. But when these familiar methods were carried 

on into the var some ot their inherent veakneaaea gradually became apparent. 

During the t1ret rev years or the var, as ve have aeen, German decrJl)tion scored heav117 aga1nat 1t• pri .. r:y ta.~g•t-­

tJl• main British ayatema. As these 11atema became more and 

116re eecure, aucoeae in reading them dia1n1ehed. B~ 1944, the 

-cumulative weight ot d1tt1cult1ea bad r1nall7 crushed all German 

ettorta to overcome them. 

The tirat point to be noted in thia connection 1• the excellence ot British cipher secu:PitrJ certainl7 the Germana 

faced a formidable obstacle. But there ia a tUl'ther cona1derat1on. Because ct a long tradition ot aucceaa with band methods, the German naval crn>taDAl7at11 tended to regard them aa the 

ult111&te dec?tl'Ption proceaa. Enpiphermente Which were be7ond 

the range or hand .. thoda -- auch aa the one~t1me pad and 

machine aystems -- the7 vere apt to conaider unhrealc&ble. 

(Their faith in the aecur1t7 or the Bnigma 1• a oaae in poj.n~.) 

As a result ot th1a conaerve.t1am, the naval dear7pt1on aection vaa slow to grasp the vital illportana• ot machine techniquea. The development ot the Hollerith aect1on (d1aouaeed above under 1Adm1n1atrat1on ~ 1lluatr&tea the lag between 

"41aousa1on" and actu.l execution or a nev 14-&. Th• oonv1c• 

tion and drive nece1aa17 to cut through tra41t1on vere l&ckingJ innovation• vere introduced onl7 atter crucial tllle bad been 

lost, and otten depended entirely on tortu1t1oua c1ro1111Stance. 

9 
Coupled vith thia caution 1n taking up new metbnda vaa 

an 1na1atence on eurrent production. Thia could usually be 

achieved vith the lov-grade ayateaa b7 routine procedures, but th• development ot a rad1call7 nev technique tor the more· 

aecUl'e systems might have meant a l~ng per,.C'd. or auspena:ton before any reaulta were arrive1 at -- or ultimate ra11Ul'e. It 

would be a gamble -- an enterprise vh1ch the naval cryptanlyats 

vere apparently loath to undertake. 

With all its proteesional ett1e1enc7, the German naval 

deerypt!on org&n1zat1on seems indeed to have auttered from a 

baa1o dry rot ot conservatism and 1ntlex1b111ty. 

10 
• 

IQP BeRB'f UiJIM ··~WI" ID :A66767 

';\j·Jr1 . ' 

RBADIBO ElUUlY TRAJ'll'IC 

APPENDIX A 

Notea.on Peraonnel Requirement• 

In March or April 1941 a total ot 64 aen vere aaa1gned to the Raval Cipher, on a 4-vatoh ba11a. Pour more vere 

needed per watch. A total ot·4o men were aa11gned to one 

ot the eubd1v1aiona ot the naval Code, and 8 more vere 

needed. The other aub41v1a1on ot the Code had 7 aen, vorking onl7 b7 d&7. Six aore un were ntg4,d to build up a 2-

vatoh schedule. The total oompleaent\ ' dea1red tor the 

•in Britiah 171teaa alone vaa thua 165 men. 

In Karch 1945 naval decrJPtion"- total personnel requirement• 'f•r• stated as tollov11 tor current r•dabl• tratt1o 

ot all oountriea • 155, tg~)reaearoh on main Br1t1ah a7atema - 85, thua a total ot 240.l~4 

Prom Janu&l"J" 1944 to J&nual'J' 1945, th• atatt ot the 

Naval Code eubaeot1on dropped boa 198 to 94.\05} 

Tranov atatea that be vaa eaplo71ng about 150 aen at 

the end ot 1940. B7 Deceaber 1~2 h1a atatt had 1noreaaed 

to about 275. Be wanted to double the number, but did not 

aucceed in 4o1ng ao. In Pebruarr 1945, he remark• b1tterl7, the total nuaber(gt)peraonnel in the entire CJ'J'Ptanalyaia aeot1on va1 275. ts6 

,-

11 
; . r.~p-· UF ID:A66767 

: ·.•1t , .. 

J ·v.;1 --------------

•. t.r •' ,..· 

DADIBO EIEJIY ~IC 

APPENDIX B 

LIS'!' OP BRITISH AMD COJIBIIfBD SYS'l'BllS 

BAIDLBD DURING TBB WAR 

The tollov!ng 1ntciiemt1on vaa taken troa T-517 through '1'-520, 

paa11m, and troa I-·12 and I-93. 

System Ge1'19&n Oovername 

Naval Cipher Koeln 

lo. 4 

B&val Code (braun and blau) No. 2 Muenchen 

Combined Cipher Prankturt 

Bo._, 

Interdepartmental Bremen 

Oipber 

Interservice Dansig Code 

12 

Re•rks 

First read mid-October 1939. 

Peak reached 1n 1940. Increasing d1tt1cult1ea atter 

January lgJi.2. No longer read atter 111.d-194,. 

Read vith conaiderable auocesa, troa start ot var to 

D•ceaber 194,, but V1th 

frequent gape. Bot read 

atter January 1944. 

Introduced October 1941. 

Read about 8~ from Pebruar7 

1942 until 15 December 1942. 

D1tt1oult1e1, then aucceae 

in April and 11&7. Syat• replaced in June 194,. 

Work begun m1d·l940. Read 

aometimea up to 10~. In 

tore• until end ot 1942. 

Apparentl7 replaced interdepartmental Cipher in Jul7 

1942. Bot being read b7 

November 1942. 

.. - .. - -; .. l ~'";. ', 

' I I jt. I'• 0 / , 1 1 

I 

I ' , 

I r ~ ! 

l t I · " L i. -:- · Li 
S1atea 

l'laval Shore 

Code 

Pleet Code 

Mersig• 

Bentle1•a Phrase 

Code 

Government Telegraph Code 

Aux111a:r7 Code 

Delivery Groups 

0•1'11&1'1 Covernaae 

Stettin 

Baaburg 

Gallien 

Tatra 

Alpen 

t • ~ 

Re•rka 1 -~\ 

'' . Worked on vi th 11 t tl• euo -t \ ·. -- oeaa in 1941-1942. Volua• ~ ot t:rarr1c amal~. · \ 

Worked on thl'ouihout th• -.~. Ver7 little tra'ttio ••re., :reeulta. Attempt to read\ 1 

Borth Atr1oan landili« trat-1. 

tic v1th captured co4e-boqk .·., unaucceaetul. owing to., ex;- I>·. 

tena1 ve uae ot cover~•• iii ·. 

text. '· ·"" " 

' 

Work begun spring 1942. \Read currently trom start ot\1944 

to end, except vhen one-till• 

pad• were ueed. · 

Worked on 1n 194,. Wo*" 

stopped in May 1944, atte~ 

1ntroduotion ot one-ti .. pad trattic. 

Read vitb aoae auoc••• in 

1940. Nost ot trattio tranaterre4 to Naval Shore Oo4e' 

in 1941. Work stopped during 1944. 

Worked on at sta:rt of var. 

Pinch ot code-book in Ootober 

1940 led to current -reading. 

Worked on from ata~t ot var. 

Otten u•etul tor r.e.d1ng other a7atema, and.tor trattio &J'l&l7aia. Re&\\ currentl7 

at times in 1942 ~d.194,. 

lot read attar Peb~~7 19-4. \ 
• WQP, Beimt 1Mfb\ 

(Torpedo A/O 

Code) 

8•11 Shipa Basic Code 

Cot ox) Medox) 

Poxo 

Loxo 

Traxo 

Bcco 

Brid.tord Code 

German QoverD&ae 

'l'awiue Rhoen, also 

'launua 

Speeaart 

Hunarueck ~ 

Eitel 

(Loxo also called 

Deister in Med1t. 

area) 

Suen tel 

Harz 

Rue gen 

(Pq 00,) 

(Pq 008) 

14 

Remrks 

Worked on in 194,. Vo:J.ume 

usuallJ too amall tor current reading. Work stopped 1!1 1944. 

Work stopped July 1944 -- volume too BJD&ll. 

Mcst ot this trattic read. 

C\ll'rentl7 in late 194' and 

throughout 1944. ' 

Coastal convo~a, ch1etl7 in 

Liverpool area. Out or 

torce September 194,. 

Apparently read up to th1• 

time. 

Pinched trom British 1peed- bo& t in November 19~·3. 

Trattic between Adm1ralt7 and 

tvo steamers 1n Sweden, alao 

battleship tlottil&. Copiea 

aent to outstations tor 

immediate reading. 

Uaed betveen "Sh1pm1nder" a.nd "Shipmlnder London". 

App&rentl;; read. 

Interall1ed. Used 1n landing and aupply operations. D1tt1oult to read becauae ot 

man7 covel'D&mea and abbr•-

v1&tion1 within text. 
• . !GP SBSRilf 81J'l'RA 

S1atem 

Combined A11ault 

Code 

Combined D/F 

Reporting ayatea 

Combined Cipher Machine 

· ._nF ID:A66767 ·y,, . j 

~vi 

German Covername 

Tauern, also Altona 

Stralaund/Kolberg 

Ulm 

15 

• I 

,.-.., ~ ~ -- ,-..-.,.---.. 1 l:-J ., tr 1' ~~ 

\ . '1 • I I•! . \ I • _,.,I I • I I 

,- , .. i :j l; ..... 11 ·" • ' 

' i t• • : : • \ I. ·- ' l.--:;> ...,,..- ._ ._, . _: • 

R••rka 

Uaed in North Atrio&n and 

Bormndy landings. Special 

ayateaa tor Atlantic and 

Mediterranean inV&lion 

coasts. Traffic in toraer 

pe.rtly read in tall 19-4. 

P1rat appeared Auguat 1944. 

Reaaone give: 1) lack ot 

personnel, 2) trattic not 

operational. 

Worked on trom May 1944 to 

Janu&l9J' 1945. ?iot broken. 
f',.1

n, .. ·-1. p\fREF ID: A667.67 · · !e1' sEeBT 'tlftfM b U I 

READING ENEMY TlWi'FIC 

APPEND;g: C 

Berlin, 20/1/1937 Part ot A III b 2128/36 Top Secret 

1) Tos Abveblt III t Veat 

Subjeot: British number aeaaages 

Reterenoe: Abvehlt 1579/'6 Top Secret III t Weat ot 

2/10/19J6 

\ 

1) The British number aeaaages which you sent could not 

be deciphered, since they alao lacked all the ch&racter1•-

t1cs eaaent1al tor decrJ"Ption (auch aa call signs, or1g1• nating stations, receiving atat1ona, time/date gl'oupa, trequenc7 data, datea, etc.} Moreover the amount ot trattie is not autt1c1ent to permit a break bJ .. ana ot atatiattaa 1 data .. 

2) Again ve viah to ••ph&aiae the tact that as tar i!P.1 

Ital7 1• concerned, the Ger•n lfaYJ' d1aola1ma all 1ntereat 

in British Naval traffic owing to the auapenaion ot intelligence activities (B-Dienat) againat Bngland. Therefore 

the Ita11ana are under no circua1tance1 to be allowed to 

torm a ditterent 1mpreea1on. For thie reason it ia requeated that the Italians be informed that they should no longer rela7 a117 Br1t1ah trattic to us a1nce it will not be deciphered here. 

Besides ve have no interest at tb1a time in British trattic. 

2) Pile under A III b !op Secret 5-1 

16 

(39) Signature 
BEADING ENEMY TRAFFIC 

APPENDIX D 

"OPERATION STRATFORD" 

(Extract from review of work done on Br1t1ah a7atema 

from 19'9 to 1941, vritten by Tranow) • 

••• In m1.d·March the Anglo-Prencb assault on Norway -- known by the cover-name •Stratford' -- vaa learnt of 

through Xoeln (Naval Cipher #4). Standing readineaa 48 

was ordered tor the troops and 95 tor the convoys ••• 

• • • As soon as the (German) attack on Norway began •• 

it vas possible to read currently of almost &11 the 

Br1t1ah ••• countermeaeuree. !he proposed landing tielda 

.•• vere known. ~he arrival of tranaporta at Harstad 

was deteJtM1ned exactl7 to the hour. and ao tar in advanoe 

tbat our ovn (1.e. German) torcea were able to attack 

them.· 

The atrategy or cooperation of the French and 

British surface toroea and their combined action in thia 

campaign vere also revealed through Jtoeln. Even the of'- t1ce~1 in command were determined bJ means or this traffic. (67J 

17 
!GP BBSHn 9l4'fh\ 

l!I 

BEADING ENEMY TRAPPIC 

Reterencea 

I-12'- p. 1:5 

T-514, 22 March 19'5 

T-514 

T-515, 2' Karch 1940 

T-514, 5 September 19'6 

T·516, 4 October 1941 

T-517, 7 August 1941 

T-517, 22 11&1 1942 and 4 Jlarob 194:5 

T-517, 6 March 194' 

I-146 

1-12, p. ' 

T-519. 9 December 194' and 10 December 194' 

I-12, JJ• 5 

CSDIO/CMP/r:J7 

T-519, 10 December 194' 

I-14,, p. 7 

T-5191 l August 1944 

T-519, l June 1944 

T-517, 2 December 1942 

T-520, 8 Ja'nuar1 1945 

I-12, p. 5 

T-517, ' September 1942 

T-519, November 1944 

T-514, 2' September 19'7 

T-514, 6 January 19'7 

I-12, pp. l,, 14, 15 

I-9,, p. 10 

T•519 , 

,. 

·-

T-514, 6 Jfa7 1935 

T-515, 8 March 1940 

T-514, 22 Jlarch 19'5 

T-514, 27 11&7 193, T-541, 25 Auauat 19'7 

T-514, 1 1une 19'7 

T-514, 5 June 19,7 T-5151 18 July 19,9 

T•514, ,0 Jfa7 19,5 T-514, 22 March, 'O Jla7, and 12 November 19'5 

18 
.. 

f Hl 

40 

41 

42 4, 

44 

45 

46 

~~ 49 

50 

51 

52 

53 

54 

55 

56 

~ gg 

61 

62 

63 

64 

~ 

6~ 

( ~) 70 

71 

72 7, 

74 

+g 

T-514, 9 September 1935 

T-514, 9 July 1935 

Tranov•1 Report on British System vith 4-place rec1pherment, 1,·April 19,9. 

Originall7 a part ot T-517J tiled in 1ta 

chronological poa1t1on in T-515 b7 OP-20-G. 

T-514, 2 January 19'7 

T-514, 6 January 1937 

T-514, 2' September 19'7 

T-517, 1' October 1941, p. 3 

T-517, 13 October 1941, p. l 

T-517, l' October 1941, p. 4 

T-517, l' October 1941, p. 7 

T-517, 13 October 1941, p. 8 

T-517, 1' October 1941, p. 11 

T-517, 13 Ootober,1941, p. 12 

T-517, 13 October 1941, p. 14 

T-516, 23 January 1941 

T-516, 19 September 1941 

T-517, 11 November 1941 

T-517, 21 December 1942 

T-519, 31 May 1944 

T-519, 2 October 1942 

T-517, 3 July 1942 

T-517, 3 September 1942 

T-517, 8 January 1943 

T-517, 6 February 1942 

I-12 

T-517, 4 April 1942 

T-517, 12 May and 5 June 1942 

T-517 1 20 Auguat 1942 

T-517, 16 December 1942 

T-519, l June 1944 

T-517, 8 January 1943 

T-519, l June 1944 

T-517, 19 March 1943 

T-517, 19 .March and 2 April 19•' 

T-519, 1 June 1944 

T-519, (date uncertain, late 1943 or earl7 1944) T-520, Jlaroh 1945 

T-519, 18 May 1944 

T-519, 16 June 1944 

T-519, 5 October 1944 ~-520, 9 January 1945 T-520~ 10 March 1945 

I-141, p. 2 

I-6, I-144 

I·93, pp. 8, 91 

I-6'- pp. 151 16 

I-147, p. 25 

I-165 

19 
• • 

REF ID:A66767 

wer SBea' .,._ ., -·1· r· -~ ·n (fi) '8fi!RA r2 r~~ u . ~ '! i:· ·i \-:1~ ru , 

uUa u ~( rill~~J~lC ~ 

!:

8g3g

7

! 'l'-516,, (undated'- March or April 1941) · 4 'l'-520, March 1945 

'l'-520,, 9 January 1943 

I-12,, p. 5 

'l'-517,, 13 October 1941, pp .• 7, 8, 9 

20 
• I ... RELATION OF. GER~~N.{}..-QF'"] CQ,lViBINED CIPHER TO 

ALLIED SHIPPING~S~?~!ltE'Rr'LA.NTIC 

--------

&eb ~ All important convoy traffic ~ ,, 

. . 

~Mar ,'. read·: Feb - Mar 1942 ~~~~~~~~ 

.~ 

j~u!§j Naval cipher #3 80% read 

~ ~July~ June to 15 Dec. 1 42 

' ~ iAug 

l._ 

·.1 I' ;set! ,, 

Oct ~ 

' f.Nov 1 Introduction of ciphered 

tn-~c-Jrn-dicator-groups-l."5/I2/~ - - ·j· 

--=r 

I 

1q 3 : I - Decryption difficulties .1 Jan ': in Dec. and Jan. '43 1, ______ ......_,.,,. _____ ~-· 

i.~ .. Feb Considerable success in reading combined Cipher #3 Feb-June 1 4:;-------- ~ Ma.r Data gained in time set U/B's 

:i Apr against convoys r-----~ ...... _._. ~ ~~"-~ ··- ~=~ -·-. 

~ May " ------~-......-.~ I il June11 

I Change in system 10/6/43; not read henceforth II-'"-=• ~~---r. 

j July; J 

~Aug : J_ 

;; s t' ' pe · ' ' 1' 

:! Oct 

,' " 

!' Nair 

; 

. I ~-

~ 

:· Feb Mar ·.! ~ ' 

~ Apr 

. May I ~Thou- 100 200 300 400 500 

'sands' 1 

~'of GRT , / . . I • ' • . i J ---II--"-' __,.~,__.i.,h -l...--'=--,_..i-,,,....._. __ ~a71..-r,..~r~a:-..;;:~-.· I ' ' -:;or..·--""""" • •t•-'!C"--.:i.it::o.- i ' .._ lr• I ~ ::.. . - ~- -

600 

. t ...