e:se1&1 

X. t'roblen pre!!ented 

lh&.t. i• t.h-. 11ecurit7 ot enciphered intern5l retsrenceea 

ai&natUl"et1 addressee, &nd me•sage numbers? 

ll. li'acts bearing on th• CU• 

l. a.,terence•t •ignature• md a.d.dreaeee are buried in the nieHa.ge 

text and enciphered in t.he eue e7etem ae the text. propel'• 

a. ?t i• possible to predict the internal. references on the basis ~t ext.enu\l characteristice of the tra.ftici 

a. li&naturea and addnsaes can be predicted t:ran tho a1.ations 

ot origin and d.e•tln.:>. t.ion. 

'-· .KeHe&e numbe:t"a can be predicted tl"Olll the tile date/1.ime 

'· Jrethoda ot 1-.olatinlJ; re.terences tl'Oll. the text proper tend to 

heCQDle •tereot)'Ped. 

lII. nl1CU9aion 

See in.cloeure 

IV, Conclu•ions 

Pnt•nt 111.ethod ot enciphering references :h cryptographioall;r 

inaecure. 

V. leCOlllllendatione 

l. 'the rules ot eco~ ehoul.d be tGf>haa:h:ed to all persons 

J+iJJt>niible for inHrting references in m.ese&ge'I. 

a+ l"1breyiation• ahould be uaed wbereTer feasible• 

'· A 9J)eoial addre•• and eignatun code directory should ~ prepared ant! u.eed in oonjunction with the eame system. used to enc pher the 

text proper. 

peclassified and approved for release by NSA on 09-23-2013 pursuant to E.O. 1352§ 
REF ID:A71933 

nae wrd !Jlere151• 1. used in \hie •t.ucb' to include tho•• it.au which 

arre not an integral par\ of t.he intonaatJ.onal cont.enta ot aeaa1gu1, but. 

Wblch an added for routlnr. and id•nt.i tJi.D& jmr.poses. Reter.r.ce1 U7 be 

atemal to the meeeace text or 1nt.emal. !hey U¥ be encipherecl or in 

tbo cl~.· Under present tJ. s. A:nq proce!U.'!'e•• enciphered inton1al 

refe1"9nceli consj at. of addrer.aea, •!cnat.u:rea, and aeseagio l'l\lll'beru. l 

Unanolphered ext.em.al reference• conalet. ot part. lndlcationi a7atm 

' 

iadl.eation, oall •i&n•, tranaiaalon inetruct!one, 1roup count, 1U1<1 tile 

date-ttae. 

• a • n r u1 Z' 1 •'« A H·---

1i. t.he appm.dix to t.bi• at.uq an N11Pl• :rt1ference• of actual t. l"&l't1c from 

U. S.\hweat. raaitle Ana, t.he Wori.h Ur1can Area, •roJ.iean lre 1., the U. S. •v. and t.he Brlt:lah. A C01111iden.tion ot aever&l. or th• will 1el'V'e to d9-

a11'!.be 'fith• ramit!eatlon• lnwl•ed 1n the t.eru addneH•• aignat.u-ea, and 

lllldl£•-mnber11. The tollowing ••sac• Ulwst.rate• a basic tJP• ot re.terencei 

PQeltl cRARtlF. ~ T.rO FIVt. SEVEX Zi.1l0 FD' CHC6 S~A sdti irlCAnTRUR TO CHIEP 

at ST.U't •J.Jt mPa\RTfll!M r AREff 

n 87 be &nal,rced .. t9llow•• 

••ace nuabera CffARLtt TJO "t":~o PlVi SEVER i'.ERO ( C-22S70) 

Ot11lftat!ng oltice1 OHQ SWPA 

11.pa:ture of sending autbor1t.;r1 cmD IU.CARTHUR 

i1Nree11 10 CHI:F 01' 3TAP7 -.7A& OiPAl'D!1:.NT 

,,._ basic tn• M¥ be 1111pli.ti•d in -CV ..-a.ya. Ttw addi·eas 1147 l: • aupented 

to tnel.ude \.he chain ot commsnd, to inolude relq 1ut.1""..act1one1 etc. Thia 

i• Uluatrated in t.h• tollcnd.ng reference1 

PAUi CG HQ THIRD SVC carm AS1 IALTDIJHE ATT m:, sgc Ar.n IfiTELL :>lV PASS !O 

00 PHILltc.PHI~ OJU>RARCZ D!STRICT PRl:t..\D&lPHIA P:&IM PROV TERRY t:SG lfR FOUR 

aao m PAllll 
REF ID:A71933 

Certain 1'9ferencen are •••ential tor routine and ident.lt,1na J:U?PO•••· 

The7 AN •c1phend becauae thq nftect. the battle order and orsar iation 

ot the U. 9. 4n17. ' ccaplete lccowl~e of rete:rencea would actua) 17 'N 

a pieture of the U. s. baJ u apreaaed 1n it" •ignal coi-.unieatic n BJ"•t•. W~cee an al.eo enoiphered bocauae a c:lear Tetosioa 1F01..lld provicte en_,. 

trattic aml,r•t• and eJ7Ptan&l.J':st..:1 111 ttl clues tor intarpr..,t.ing W!lf aolrl.ng 

ov tnttle. 

S.wner1 there are cert.a1n dqera inherent in the ffr1 tact ot .nciphezunt,. :rt will be the purpos., of' t.h11 paiper to mpecltical.17 analp·• t.bo•• 

·danpn, el! to propose certain changes which w.lU alloviate t.boae danc•r•. 

tt. 11 rwcocn!sed. that the probltr. under cone1.r!erat.~on i• incx~rlcabl.7 

Ued. up with the concatenation ot aecurity ot all co~unio~tions proceduree1 

and that t.he eecurl.ty ot an;r apcclfic procedure is depenl"ent 1n a sreater or 

, • m vsst t -· v 1v • n at ... --------- 1 (cont.•d) Anal.7ai• of' thie reference 1.an 

~··· --di.ate recipient 1 CC H;; TH!RJ> SVC C01'D ASF BAI. TIJIORE 

m.Uu.t.e nclpient.1 A'f'T DIR SIC A.'11> Dmil.L DIV 

le1.q inatruct!.ona1 PAS' TO CO FHILADtl PffIA. ORDN'AliC?. MSTFIC'f 

PlfltADELFHIA Pi'lll 

!he aipat.u.re --r al110 be aupented to include the n.ame ot the orlainatina 

ott:lce:r met t.he chain of' camr.anc.' u in the tollowint: r«itP.rcnce: 

PABW J'R()11 roCJtITTr.E TO AIM'-OLD ~ SPA.A'l'2 {l~A.'>? EIGH! T';-0 n:o S1':\ "El EIGHT) 

ltQtD.'D Ji:ISEIHOY11t'R tt.F.PERP.WC!:! Wiltt !fflfi,E tF.RO ~EE SEVEJI FIVE llAY 1'115T PARER 

:tt. abould be not.cl that t.he set. of references 1• contained "1.tlain PAREll' •••• 

PA.JD. hncUoning u M adjun~t to tbe eignat.un 1• t.htt IJ1Rbol .t'or a branch 

or $partilaent. .Ill u.apl•1 

PAltFJt em SFSI£ IICtf.S CSlCO PARER 

r.tnalq1 rete.renoe1 u7 contain the dietr.lbuUon ot a ••rtHB•• 

PASS TO Cl RECIPTI<:m STATIOR PORT C&OROt.: DADE VAtm.AID PD ALSO J· X)Jf.D TO 

CRtE1 OF TJWISPOttTATIOW W.ASB D C OBA CG ASP WASH D C CO Rii'SC EIJrollTON ALTA 

Pdll 
- - --- REF ID :A71933 

l••••r degree on the aecurit:r of every ot.hor procedure. 'ftl.u•• chance• 

in procedare• involving eill ei&n•, fftl(\uenaie•~ .nc1phement. ot iqat• 

1nd1catora, etc.,, would verr 1reat.~ atfeet. the anal.7sie ct enci11bered 

...atereriaeis. lot.wit.hat.anding, there are certain aoditicat.ion• whl ab can 

be a4epted. to t.he enciphered references "1\ich .Ul .U.tna.te llOllo• ot the 

d:S.1advantage• inhennt in the preaetit pNcedu':"Q • 

... , _ 

-----
REF ID:A71933 

PilT I 

Preeent Procedure 

""' preaent practice in reg&rd to 1.nt&mal reteronc-es 1e io b11l7 \ha 

~the~ in \.he aoHa,ce te.A.t. u.d mc1pher t.h• in the ••• a71.t.ft 'llh\.ch 1• 

uaec! t.o encipla~r the meaeqe text. it.aelt. 

tho 01'7Ptanal.7t!c vulnerabU1t7 ot such practia• 1• •ll ll'lOllD. The 

Mee Nferences - due t.o t.he Dft.t.ur• Qf ca.aunicatbn - .r.re uaecl ae•in and 

tlClln, 81'.d const.it~t.e a atere~t.»e.2 A• auch, thq provitie encn,y er.JPt.-

ua1¥•\a with probable wont. tor att.aakin,g our q•t.lq. Howevur. it 1• not 

OldJ BllCea•&l'J' for the Cl91V CrJPtanal.7eta to 'know what j)J'Ob&b}.e Wrda to 

tr;r, bu\ also bl what aeaooges to t.r7 th.ma for probable words cannot. be 

tried 1n 1i01er, -•sage. The great volume ot traffic Nuet. be dol:l.mtted. 

11ae wlnerabilit;,r Of llDOiphered Mferel'lC&I ia not tt1at. t.he,J U.et., no\. that. 

caz-t.dn wor& are pNbableJ but. that it i• poeaible \o dt .. eov1w 1rhieh 

.... a:. oont.aina • r-art:lcul.ar nterer.ce or ... or ieerl'l!"Elncou. ~ this 

S.a the orux ot t.he preaent etu<J7. All ~11• which follow• ~ • based 

on tti.t thesis. 

lp•ei.ticall71 the eecur1t7 dieadYantages ot ene!phered roferences 

under the preaent procedure re•ul t from. two ttOUrces r 

(1) Deduction• thnt can be made troa a correl.a.tion ot cel"tain external 

teatarea ot the tranlld.t.ted tom ol tho •••S8-!e to the enciphered 

nteracea. 

lih:t i~ ·ooi;;r:l; ~•t•rr~d to ;.. ater;,,t1P• begiivrl.nf. .. and end:.ngs are int1n1-

\nlnlal in illf>Orta.-ice when compared to t.ne stereotype ot re.t'eruncea. Alt.hough 

caillLOll 'bepnninsa and endinca 11a7 b• composed ot • tr.,q,u.ent ~:re.ph,. a mrd,. 

or at .01t a 1~10rt phra•e, enciphered references U7 o.:Jnat1tuto a paragraph., 
REF ID:A71933 

(2) t>uduct.s.on• \h•t. ct.n bo Melo t!'Oll the eoJ"Nl•tlon ot kr owled&• ot 

,.teren.coe ot a llOlY~d 1,f11tua. llitb t.ht11 references of an un.a~lftd 

••to:;.l 

lll&t. are the e.>rrelati!>n• \hat a.an b• .. de bet.ner:. u.temal featUl'el 

of tt..a t.n.na.it.t.ecl tom ot t.h• ...... and enc!pl..ered rol•re.ncei a 

'll\e,t U'GI 

t. 0Drnlat.1on bet.nan at.a.tion or orlc1n met hrtemal •.tanatlll"Oe. 

ii.. Cernla\1011 bet.ween nation of dest.1nat.1ori end lnt.enaal ad.dre•••.•· 

m. Correlat!f)n betlietft til• dl!t.e/thio and int«·rr:al ...... mmb•r•. 

j;,; ·::·~ecu;~~1 ~t Ut~ 'ii~~ ~;;e will be acr.d-;;~:;Ta;.;;. piipcr. 1be ~ ln.YOl.Yes t.lut equat.ln& ot Nforer1ces ot one •~:a 111.tt: references ot 

..,t.ber et:18\9#! CJr. t..he b&ai• ot utemal eharaet.el"iatlen or the •••MA•• in 

tp1\ion. The nlat1on•h1p ot stem.a.! charact.e1"1•Ucs to ea.ch other 11111 be 

41Nlt. with In anot't\.,:r- atud,J'. The •eoand aource bri.118'• UJ.1 t.hct !tea ot d1tter- .U.t~ort in reterenoe proc:edutea ksed on t.ho HCt.lJ'i'\,y ot apte•J that. ia, 

lt tlJO -=• .;;ra-c..t..ares U$ '1Hd "1.t.h .:JC~!?.\ u with Sir.ctJ't, lf2C.-5, Dl'8t, and 

8 Ta! Code., an ab111 tT t:> 1"C.a.1 •asage11 in IQ.~A or 1n '!..!) Te-1 rode 110uld. pro-

'f'ld• el.lie• t.Jr 'r0adi"£ tt~e JJ.gher &ftde 31'8l.CS. • .lf it could be def.endne-d which J 

~·· U8Gd tho 88D• refel'WlCes. OJ:ftslder the foll0tti1"11 tno ro!•renc~s. 

!ht tint. wu ""1- in a S!ceul! ••sap ot AJ>rll l2J t.bP. socond in A ~JOA.a-' 

••ace ot At>rl.1 23. Xt tile first. mesaac;e ns read, and it co\lld be r.iapected llllT 9%t.ernA1 eheract~riat.1.ca tha~ ~ .s.tlar net ~t r.teror.ces •t•o 1n \.'le 

..,ond M•8'1"'a -ui~.n the tlrst. oould be u.aed ae a erib tor ~ 1.aond,, 

lpril 21 Ctrcm .. "'VJ> seat.Ue "::uh to co '1-d svc Cad lllll.U110re} !JOCUM 

P.AIFI R£L\! BY .i.CS :.4,.i.TTLi nt\lt TYL.ltti. G4:i.b!A~iJlllO t:,I~B:.i:J'a AJ.S fU SlVi'll 

m! TH1tEi :..::.V-il: Jl'1t"!« ~D !ULTD!v!lf Pi.SS 'lO CO ai..Ci:..T;TI,'fl 511'.\TI:lf PORT GtOtO~ 

81Di 1Wr!t . .t';~ ~D ,J,f.r) lt.:zr.-....:-::o TO ~n:~ OF Tl;.;~POlil7..\TlOfJ •ASH D c CHA co 

dt WASP. 0 C QI,.. CG RWSC n'tlCNro1i 41 TA .PA.'l.FJJ 

April 2,; (:I'WI :-V!l, kt er; Third !VC tad !a.lt~:rti :::t;.J7l-nd) ~m.!~ 

PD ,.... ftL!i~ CClllolf)JJ(f) 'F'J;J' ~StV:-li nvt: Si.'Yf ... ax Em? Er·T l!JtL1'!' P!) PAID 

B?BD SVC cam PASS ro CO J.ZCSPfl\)N .,,1 ... nrni f\*-1 Gr.Of.{;'. iifi-.AO... !:J.JiUA.lfD ISO 

GllCllA.f.:D PilJBAIEj At:. ~:i CHil.I UP TRA:r;ro!'!Tn."fI;JN ·,1;.~:HIOOT.J:'t 0 c c.:fA CG 

Ar IAd D C QlA CO HllS.l SDl1..:trl'ON C}f.~ C'JIKAN~IJiG \ifPICe.~ 1tf.CEPTIOR STATION 

l'OIT 0-r.OP.Gr. flEA.tjf. JlAJllt.:. tii" . .ND C.)::'..;,~r:riOO G.tlfi..; ,.1, 'fti.IR!l 3t;lVlCi:. CV!:nUJll> 

UL!XMOP.:. t!r..:tn Aftf. ;: .ilUi:I 

_,_ 
REF ID:A71933 

'l'be eombinatton ot t.b•" eonelat.ions tom a cca.poaite ot intormat!.on that 

tlM be ued • a 017P't.ar1al7tio wed.I•• !her• 1• &1110 an additional ..,unt. 

ot btarmat.ion pl'O'Yi.ded bJ' tbe deduction• ha••d on I. tt, and I:tI. !ftda 

w1l1 be conlidend u1 

rt. dD11at.eru 1ntoruti.on proTJ.ded b7 1. It, and ??I. 

•• the length of the; Nf81"9ncaa 1n a •1.ncl• aeasage 

1». the poai tion of nterencea in the aaaage 

• 1. Mt.hod• of i•ol.ating rete:rencea trom the t•._ pr-..iper• 

t. CorrelaUon bet:ween •tation ot origin and internal 111gn.aturea. 

I.Dtemal •i&Mtures M7 consist of the name ot t.."ie originating o.ttJ.c•r 

oi- ottice,, \b• namt• ot the ottlcers in the ohain ot comi\.nd and tie namea 

ot tbe 11endln1 authori.t,y.4 

'Ike staU.on ot origin at. present can be detendned hor::t. t.he ua1 of l'ised 

clear oell .tgn., .,,,_ch are allocated in a d.tftnite relal1oneh1p t.:» tht area 

in whleh \he •tat.ion ie located.4a 

lt. i• neaesea17 to know whett£er the call alp or the aendbJ,s •~tion 1• 

the oal.1 alp of the originating st.aUonJ tor the •e•eace- f1A1 be 111t.ercepted 

on th• MOOntf 1• ot a rel.AJ• Rcnrner, t.ran..itt!na in•tl"U.ctiona lfbich occur 

1n cleu pl"D"lide a aheck on tbia J."01.nt.. 

TU •icnat.ur• ot 'the •ea.ding authoat7 ie the aoaaanding of'tieer ot the 

area. Ill• ume l• OGmrllOn kDD•l•d&• cad W1uall1 appean in rn•'t7 ••••l.P trom 

a g1Ten •t.Uon. Ollt of 30 (al.aoat oonoeau.t.iYe) aeasagea a.ud.ned f'1"01A SllPA 

• eamed t.ho algnat11re JIACARTHURJ 1& wttN SCD lfACAh'T»UR • 4 were Sl<mhl> 

4it;!.hi*;.1Uah ;.;oc~du~~; ';~s n~t 11e1;:rti~e~t nw; ~ ... ~~;turea. !he7 are oaltted al.together. 

4anda i• in areat. contrast to the Oeman use ot a&ll •ll:ns which c~e ddl~ lrNiipecti•e ot frequenc7 ehanc•· r:i U. s. Rav, eall *1gns of forces afloat .,.. norma.117 enc1pheredJ o&l.1 aigns of •bore activities arc uauall1 not ene!phered. 

SI.Cl!! 
' L - -- -- - --------- - -

REF ID:A71933 

WACAlmml, n&d 8 .. ,,.. 'PROM llACAR'1'RUR. 01:d;. ot j2 ae•a&•• euaine:l tra the 

•rth Atrican AJiea, 16 WN SIOK!D WILSCllJ and l4 .. N S.IGBill m-:va:Rs.s O\a,1; 

et '1 ••A£•• --1.ned .trom tho European area, all )7 eontained !l:SEIHOWER. 

Xt. la almo poeaible to aake a aorrelation bet.ween t.he .t.ati'ln of origin 

utl \M o~ginatina officer and chain ot co:mmand, but not. from c1ll •icu 

alone. !be ao:rral.at.ion llU81. be worked out in con.junction w1 th s.r•ta used, 

elasa1ticat1on, kind ot tra.:f'fi.c, length of aessage, tile date/t1Ji1e, etc. Howenr, al'.l these item.11 are a:nilable on intel"Cept. The de~ree ot d1tt1cult7 

in aak!n,c · t.hie klnd ot correlation depends on a knowledge of bati.le order 

*"4 trattic anal.7•1•. 

hw •Sanat.ure• other than JUCAR'.l'P.l.Ht appear 1n the ,30 ••••age·• e.xudned 

trm S':iPAJ howner, there were 20 u.aee ot OH~ S\\'PA u the or!cinatiug otfice 

.nd l inatanae ot 00 USAFFE. 

'!he nmM• ot yaJ"loua onainating otticere - SAWBP.XDOE .... SnTZKR ••• Jr:A.UCH 

.. • • tllOUNTFo:RD ••• - appear in the aessage11 trom lorth Atrica in conjunction wtth 

the •ip.tul'9 '111.SON or DP.VERCJ. TheN were m rep.tit.ions. On the other hand, 

the b.ranch or department •Jmbole in the lortb African 11essagea can be plotted 

u.d. eottalat.ed with the •ignature of the •ending autho:rit7. D:&\ERS uaea •Ja1-ola that bepn IA--J WILSON 1utea •11tbola t.hat 'bqin FH--. Tl.ue there are 7 

!n1tances ot CT.TE l.AAGE1 4 1n1tances of CITE IAOAP, etc. il'l tho DEVERS aeeaage11. 

'!hen an ' in•tanc•• ot CITE rHKOS. 2 inetancea of m·w, etc.i in the WILSCB' 

••d£e'!t.' 

rlii!lllRR ··- 8 I I l II I I I ., ' 1lil l I &1 II .... 

SC:lpher t.ra.t'tic on tbie eer1es wu not available eo atudy could no't be ude ot 

corirelation between ext.ernal characterletic• of t.he aeseagea in an effort to 

predict. precisel-7 wh! ch eign:ature waa :1n a &1 ven aeseage. 

6Dt.---vER1S 1111bol R.\.-o- undoubtedlJ oomss from N orth A frica. Wij.SCN'S FH---

aq- be the PH of AFTI·1. The l&•t t.hJoc,e l•ttera of the •11Dbol are a tri&raph 

probably representing the branch ot ~ .. he service. Th\ia Fffi:JIG 1• pl'Obab~ 

ll:JgineerBJ FHSIG 1• probabl7 SiFAl Corpe. 

I ' 

S!Cft!! 

- 'I -
REF ID:A71933 

--

arid chain ot·---.nd.. !bl• l• •no• veey cleari, in the Appendtx. tis addi-

\!on to 'BISDP.0-~'l, which arpears in &11 37 aeaaagee, w find l!i occunence1 

•f PJtCJl 1.Elh 6 OCCUIT&nCOS or Flnl SPAATZJ 4 occurrene".?9 ot !'ROH COBSiJ 2 

ffcut'l'eb.c•• ot ~ 1lOSS1 a• well u aneral other •inel• occur>"WJ.cea. 

:a. CDrrwlation between lltatl~n ot destination and intemal ad1lre1101. 

Aelllis11es cansist of the name ot the ult1Mt.c nc1p1.ent.,tla•s chain of 

__..and, t.be hnediate recipiont.1 relq in•t..ructions, and. the d!.nr1but1on 

·~ tba •••8&•• Ro all or t.heae it ma are oontalned in &rr¥ one mea•ag•. 

b s.a·the prerlous correlation, the tacte a.rea 

(1) Clear vall 111.gna and c:lear tranlDi tting inat1-uotiorls delineate the 

-...t1on or deet111ation.' 

(2) The loaation ot the station ot destination is cle't.erm!ued b,y the 

pocraphioal •••ianaent of call a:lgna. 

(') A knowledge ot 'battle order f\lrnl•h• internal addresues and the 

eol'rol&tion bet.ween the station ot deat.ination and in1.emal addn••e• 

.._... in the Appendix haw been eur.udned tor atereo't1J)1!4l addre••••· 

Ill the cuo ot eaeb ••••age, t.he ul.tiu.te deet.ination ia ~AR.. 111 t..he 30 ...... 

~i Uilliidn11d COJU:n.f! into WAR tro&Tl SWPA, the tollcmin.r: a:re aoao ot the intema]. addreeMa noted• 

mru1.: 1'0fi01ilng 3t,P"tc&!" ra!&i iie.aage,, tlie cit:ll ii(iiiaof tbe' ":.!re£ leg ah0w11 

AID V IF6 T-!FR 

All> 1• tbe etation called, and in tide eaee le the NlaJ et.atiou with in•tructl.ona to t.ranaait the aeaaage to UR. Bl'6 is the etat.ion ot orJ-1ln. When A2D 

tirahlll1t11 the •••&&• to 1Pi1 t.he call •!.in• •how1 

m v A21> A-11'6 

illdioatlnc that 1t 1• a ma, ••••aa• and that tho orlginator 111 11'6 

llCll! 

. , ... 
REF ID:A71933 

1'0 AO'iAl-12 

~ AO'iAl 1USHI1Erou - 4 

!O A(t'JAP. !!WO ATC WASHilfeTCll - ' 

to Clltl\1' OP ~'l'APF WAR SPAMtraf'f - 7 

10 CHX&F Cl' ;TAP, WASffINrrTON J> C - l . s CRiu SIC'.rPf Al omC&R iiASRiffCTOI' D c POR GENFft~f l'IG..im - :~ 

roa J1ARS1tAu. -2 

It. CM be Men that. TO MJ.¥Ak occura 19 Uua, (or 1n •r• t.han .50C ot the 

... •&M••) -.ettmes 'bJ' iteelt and •motiae:- enhanced. Cut of the 32 Mll- ..,.1 C!Oding izlto WAit lroa lorlh Al1"1c:ma Area, AlTUR occurs 2J tiaea u an 

addreaa or &IS part of an address. ••aagea hoa t.ba luropean Ar•• do not 

atd\1 t. 81lJ genaral at.ereot.79• in add.roes. Perhapa it the cipher ti-attic were 

avdlable 1 t would be pos•ible to aake acme epecitic oorl"tilation. for 

G:lllp].•1 IQ Alll'VLD occuN 4 tJaea. U :l.t ftre po•dble to diatinau.l•h air 

trattir:, a deftoit.• aorr.lation ad.ght be tound between tJP• of t.ratfic and 

tbe addre••, to Afal:JJ,ll. 

th• C17Ptanal.Jt.ic Y\llnerabilit1 ot the correlation between atation ot 

ddtine.tlon and ·&ddreaaes 1a "fit.a.117 allOlfD in the Japm"svi ~ :",-etmus which 

wre an extc!"ftaU., eno1rhared a.ddreee (ATB) and • eeparate aode bcolt to diaau.1•• 

the dest!n•ticm (~A). The clear destination auat first. be dettii•ined. 

lattle order and Ero'.1'ledge ot put traffic provides probable addJeeeaee. 

9olu\.ion 1• 'b&lSed on a corral.at.ion between the .\t.e and the Ti)"&. 

In llOlll•! Jap t.rs!i"ia al.uo,, Ute di•tr.lbut.ion ot the m.eueage 1:1 enciphered 

int.emAll.7, u•ing the eaae qstm as the text it.salt. Thi• eona~dtutee one 

ot the mst import.ant cn7pta.nalytlc wedges. 

·9-
REF ID:A71933 

Ila. :relq au114:e p1'0Senta ~rta.tn d:lttel'Wicee ot its own. A nla7 

MCUJ'I whtn there ie DO dire~t. toru'IWllc&tion ahar..nel bet11oen tJus nation of 

orlain and et&\!i::tn ot detttinat!on. The 11ess1t.4• 111ust t~n be rcut.ed through 

.,_ 11itanaett1ary et.atlon that t.ae a d:ll"ect channel with both. Uw "lq 

•--.r• per.d.ts not onl.7 t.hc cornlation of 1tat1on. of" rleetineiion 'With 

!D.iern.i at!drti~•~•, 'but al.90 pend.ts a correlation ~twoen the rel.87 

at.a.Uon and nlq inet.nctions eaio1;rhered intem.a!.ly ln \he •••age,. It 

la on "1_, tra.ttic, IMlreovc:r,, thl\t crose-s11t.c. du.pUcatea M) be undJ 

hr the 111.tbi.a.te recipient 11A'1 aot. have t..he ••• qate :a aa th6 e>J"l&in&t.1.ng 

ettlco. T'hl• rr.A7 1.">J)osa the resj,onsibllit.1 of pa.ra~brad.ng on t.he nlq 

Rat1Qn. 

m. Correlat1,on betwuen t1l• dat.e/tiae and intern.;.1 :assace n.1•b•r•. 

9'• file date/\1'11.e iroup 1• plaeed in the cl.oar ln the praam.ble of the 

... •ace.• 'l'M arigin~t.!ns een'ter ...ua.t. file messages 1.>gical.ly ·i.n or~r 

to t!nd \hem acai.nJ \ho ncip111nt. Jlll&t haY$ a •Slapl.e and ccmvmlent. manner 

et raf•rrina to any particula.r aess~e. Hence, mes~ac• n-=b~r.s an ••tdcnod 

la Hdal order. It i" because ot th1' •eda!!:t:' t'!lat. a diNct. C<'l!Tel&tiou 

1s po!s1bl1!1 betw•n tbe tile date/tinio and internal aena;r,zo m.tberuJ it. 1a 

D&t.. a dlsadvant~e due \o tte file date/tJ.l!s in t~s cl~uu·,. tr;;r 1.ho tranmttt.al 

date/tlae or Ua.- cr,y.,t.o4..-aph1c date wcr.UtJ be practical, 7 u val,j d in u.1d.na 

\he .a=e cor~alation. 

81ee jppendlx II. 

.. 10 -

-- - ------------------·-------
REF ID:A71933 

lt ie poe11ble \o aa•icn ••••as• 11U1Bhen in llOla• n1anner oth•r Uian 

.. !'!.al order, 'but not. too teaalble. Sel"ial nmber• u •uch aN l'M>t u•ed 

lt7 tile IJ. I. l&YJ• Instead, the d&\ef t.ble ll"OUJ> Of a Mel&age funct10ll8 

.. it• aessaea ftU."!lber.' 

. Th• Ye17 tact. that there i• a detimte ord•1' to ir..tcrnal ••Hit£• 

JIUllhara prov.!.de!9 a orypt.an&l,Ue attack. The dd.l;y ave.rc..ge GO\lllt of traffic 

baa a d:nn center can b• a•certainad; and Ul8 approxi.Ret.e ileHage nuaber 

can ba- predicted. lt ~ message tram tbe or1ginatiQ£ center has been 

l'lt&d, ita number can be used u a point ot departure tor aal.culftt.ion. If 

no aes911.£e has been read, it ie ae1JUmed that. nu:aher.lnc begins 0Y1r agaln 

on or abcut Janua17 1 or each year. 

I.et. WI oonslder tho retorer.cee or 4 e.ctual ae•Mf:C a :ielecte :l at random, -. 

awl attc:1pt to corrt.lata the tile elate Id.th 1nt~rnal n\dlbar. ·-· •hall leave 

t.he tile U.e out o! our conaideration • 

.lpril 18 

PAID itAIX r::o fOUff 100R mm. NIME SPT~ SZVfiJI SIX NAUGHT PROM SClll-;ftV!Lt 

tl:IRD SVC COKD PASS Ul.TDrvll:. StlD P03 FOii. ACTluH nJHi,Ji,:; fAJHI 24499 

lprJ.1 21 

Jj&I ;·m Tl"O FIVE 111£ FOUR THREZ ~Roi! :S.Jl.!1. jJ' .\CTI~ nno. lllJUTAtT 

111£84' !PSTP Rl"T SPSTr- PAREN 2S943 

lltrll 22 

PAJIE!l IAI'i.X t .. o SIX FOUif. 'NO J":.O Sr'fC':' HPT ~P1\h !i!GHT i'IVl£ 511 nor 

lo:l'.sllYil.T. TRIRD _,EftVICl' CCP'~.\l'ID PJ.3S '1'0. BALTDluRK P03 !PT r)i PAR&'f - 26422 

lvppooa we had at Olli" diepoaal o~ the t-=> &eBB6£es of .Aprll l8 and 

April 21. To .:et \he dail; averaf e, we take t.he ditterer.a.ce be1.1nen 25943 and 

9oi;,.;,~;:\1~n• In~lniction•,. U. s. Nav,r, 19.U.. tJJC Par·:· 2039:--·r111e proe•dure n•e••d tat.ea tal•e t.ille on 2nd, 3rd, 4t.h - parta ot a ae•nc•J 

toi- part. indication ia encipheNd • . 
_..... ........ -----------~-

REF ID:A71933 

14499 and dlvi.d• bJ" 3. The r..W.t 1• 481. Thia da1lJ av•Nf• now booQll.OI 

a ;f&rclstJck "1th '1h!ch to P"dict other me••a&• numbera, To a.,proxlm.ate 

the numbers on April 22. add •bout. ~00 t.o 2642.~.. Rae! w added 481 - the 

dailJ" aver<:.£e as detendned betwe.. 'Lbe aesa.qes ot April 18 and n. we 

WO'l2l.d havEi bectn onl.7 2 ort. f'or the difference betwee?\ 264~2 aad 2594) i• 

479U 1 Thi• i~ pheno:i.enal. So precise & predict..ion 1• genera.?.l impoasible 

fJ'Dal lara\J cent.ors. In larao center.a., a prediction will be aat1at1ed with 

a V&riance ot 1001 fo:rg~tting about. the units and tens posltior entirel.7. 

U 11e ~e the dAily a,.erage bet..ween Jpl'il 18 and April 23, the figure 

will 0. 4Jlichtly higher. but &till \•ithin t.he locu3 ol 100 variation. 

let•, .-tJppoae lfe have no •olved 11essa.ges at all. at. our d1:s;> >Bal. ln 

that cue we ID.USt &aSU-.la JMuseaccs start. nl.Ubering over ag"'in on oJ" about. 

Januarl' 1. \Ye woul.d then take trattic ot t.hat period t.o work on. It we 

an ncoeastul.,. we can then uee t.he :reault.in& .ma•sac• numbers au a-oontrol 

in later pndictiona. 

1.t we have no traffic C>r U w are unable to wor~ on t.r.:r.tt1c of the 

Janu.&r¥ l j1eriod1 we mu•t. 1•t trattio anal.7ats to pve u t.ra!tic YOlum.ee 

boa J&Du&f'1 l to "the period under ooi1s1derat1on. This will pv1 an idea 

of the .a.s>vroxim.at.e aea1age n111bll'r. 

:r...t '\l8 conaid•r another kind ot col"Z"el&t1on. Suppoee •• hsre a 

aingle solved me:seqe at our d191>oeal, what aan be donei Using ~;.he meaeage 

ot 91"11 23 with the internal nlllb•r 211170, we divide 26970 b7 the number 

ot dq• botween Januar,y 1 mld 4p:ril 23 - 114.. Thia nsult. - 2!.6 - 1a 

DOW & cf.ail)' &Vel"age baaed OR Janu&17 l. Traffic WlUl'AC -.nd flow, however, 

tl:11ctuat•s a gnu;.t &NU, and 90 this fi&ure auat be a<Uu•t.ed b7 trat!ic 

...i.,..t,. lt then can be used. tor 0!"1J>tsnai.,.t1c purposes. 

-u-
------ -----------

REF ID:A71933 

111 t.ak1ng tile tble u nll u tile clato into aons~dera.t.1on, a 

n.ther Jl"Ci•• pl"8d!otJ.on can be aad•. The nmbel' 1nt.ervaJ. betwt·en 

••aacea bearing short. tUe till• ditterencea will be TeJ7 ..U. Thi• 

...na no ebanla in t.he hundred• or ten.• po1it1on ot tile•••&£• rnab•rJ 

on1J a eh&Qga in the wd.t.1 position. 

'7 

~ 4&117 avera.ge t.rattic ftl\lllle mat be a!'al.J'zed tor each c ent.er. 

Thi• bu bee done tor .U Jap Azw.7 trattic, wls.re about 2500 •e1-ies haft 

.,.. 'beat eet.ablieb.d. Bel.olf i• a 11pee!aen ohart. ehowine; how .Jap ••••ace 

nuad>en are p1ott.ed.,l0 Atter the plotti114 reaches a eertain levcl1 daU7 

.-Pac•• lft •ltiaated. 

-

• 

D. C:Oll.at.eral 1.ntomation provided b7 I .. ll, md Itt 

the lqt.h of enciph•red retal"81lcea •om.tilt.• bec:>i::ea qui ta •isable. 

Under ordinarJ aondit.ion1, it average• over 60 let.t.eraJ and 1n not too m-

.W condition• Ul' exc .. 300.ll lttedles• t.o aq, t.he longer tho 1et. ot 

Nfe:rencea, the an•t •ecur!t.7 disadvantage, tor there :ta more .~~reot1P• 

aatedal •v&ilable. ln 1ame aesMte•, the retareneea •11.7 const.i ~ut• u 

MUCb u l/'J of the text. 

!bl• lonsmt7 11 not peculiar to u. s. t.ratric. In Je.p Ariq ovar lOS '..I" 

'is t.aken \Ip b7 internal enciphered refel"Clnce• 1n addition t.o the extemal 

emd.phered routing, addreaae11 and ld.cnatun. 

I\ le possible alao to localise tho poeit.ion ot the ntermHes in a 

ae11t1e. Practice has detend.ned that enc!,phe:red references llho lld· not be 

ma; ~p;dlx ·xix •· ' 

lla.. ••H&• ot April 231 troa WD t.o CG Third Svc Old., page 5, t.his report., 
REF ID:A719~3 

Wri•d 1n the ~nc or at the end of •••sages. Tho result baa be.-i 

to ~•• the eccond tourt.h. ConTent.ioMll.7 the Jape buey reterence9 1n the 

la•t third ot a MSaage, 'Wbile Ceman• pref el" t.ha open1ng. tJeing tJPe t 

MChine, it bas eat.imated that. Briti•h references near>l7 alwa.r• ha'f e •~rt.ed 

about the 90th ch&ra.cter. Thie bu been partly due to to1 .. ueed in wr1 tine 

......... 

ane ot the cancerous additions to the reterences has been the m.ethod 

u1e4 to 1eparate the re.terences trom. the text ,Pl"Oper, eo "a to e.Uminate 

contuaion a• to what ia ••••ac• text and. what is reference •&terial. 'ftd.11 

has bean done b7 enclosing references in PAREI. The use ot PAREB for thie 

put'pO•• hu become 1ucb cannon p:ract.ice t.hat. it i• not e:u.aerat.int to 

sq that. it ;la used in over 9()1 ot all aeaaages. The uae ot P4R£N 1n pair• 

to "&resate rete1·-.oea proud•• a 10 letter crib, the ieolat.ion of whioh 

bi U1' t.e.xt will d.etendne t.he po•ition and length ot the eet. of rc.terencea. 12 

The uee ot PAHER ia •im:l.l.ar to the Jap u•e of TEXT Etm.s and TtXT F..GINS. 

Once i•olatctd, TS and TD deter&d.ne the poeition and lengt.h of the 1oterenc•• 

in the Jep meaNge. The tirat. attack and t.he ra:>et. 11Uccesetul le t.c di.8cover 

" the location or \heae two parenthetical devicea. The aecond at.ep i a to 

ao .rt.er the r.terencea themselTee. In IKll.e conditions, the iaolation ot 

TB ud '!'B i• ao deat.ructive that aoluticm tollowa in a aatter of .Jnutes. 

'!hat the Jap• realise t.he Till.nerabilit7 or such practice 1• tairly certain, 

tor traduall.J the uae of Tl and TB ha• diaiebed al.most to the point of 

41.aappearance tro.11 cert.ain center•. Kothing haa replaced it, proving that 

it -. wmeceesar.r. 

n;~ .. ~; aee~:: ; ~.:O.aents flfH'f7 ~~ ot punctuati,on~ 'Fo; ~arit71 bo .. ver, pmctuation mark• can lMt l!Pelled out.. Colllllunicationa .!!!!!,ruotiona, 

u. s, Nav, 1944. 1*C '~ 1'u. 2034. 

azem 

• 14 -
REF ID:A71933 

'the •9CIUl'it7 diaactYantace• ol enoiphered ref•renc•• have aow teen 

emeera.t.ed, 'ftte attempt ha• been ude t.o ahow how tho disadvantage• could 

- be ued tram a OrJPtana.1.Ji.ic point. ot Ti•. level"&l coapa.:rieona vdth eneq 

_,..t•• nro aa4e in order to dtaonutrate pr&ctical.l.T bow we (at tie preeent 

time) are t.a:k1.nc adYantage of deticienc!es in enellT ey&t.c:iaJ detic:f encie• 

which alao occur in our own a7atema. 'le muet uelae th~t. it • car. do 1 t 

to th•, t.blQ- can do it to ue. 

8pec1t.lcalq, U. bu been pointed out that. references enoiphe1'9d 'b7 

the 11eme qRc u the text lteelt are dan&•Nl.UI and Jeopardize t~· text 

because there 1• a direct correlation between ext.ernal char~cter1stJ.ca 

ot the aes1age and the intemul enciphered re.t~renca1, which conat.1.tute 

a .t.ereowe that aan be localised 1n the traffic and uae:l •• a cr..b. 

ft• nest step !a to coneider what can b• done.· 

.. 1, -

.. I --

.. 
• 

IZCltRI REF ID:A71933 

IA coneideriug what can be done, •au.st rephrase the question in 

the llaht of preceding exam'nat.ion to read1 'What can be c!one to bl>ck 

the correlation between .xt.ernal charactorist1ca and 911.cS»bered retarencoa? . 'ftd.• qu"eat.1on could be at.tacked fJ"Oll either or both ot t.1'0 perspect.lYea. 

We could .mekf.t a conacioue effort to dieguiae the e.xtemal characterlatica 

(AS THE GUMAJIS DO)J or we can propoee meane at diacui•in@ the reterencaa. 

There i• m reason whJ" both aan1 t. be done a1mult.aneous17. In this ,.:»aper, 

bowner, tb• probl• will be approached eoleq frata t.be rlnpoi nt 0 r the 

... ne"Yer m an.al.T•i• 1• true, there 1• a certain un:fveraalit.y .1bout 

it 11b1ch u.'kes it v&Ud 1rreepect.i.Te ot tho Jll0d.1ticat1on of cond1tir>na 

Which originall-7 ,ga"Ye riae to it. The aecur1t7 - or lack or •ecuri·:.T -

o.t enciphered references he.a long been recoi:n1aed. Various solutio!tS have 

al.ao been pl"Opoaed •• a rme4y. 

following 1 e a quotation b7 lfr. 1'. P. Medin.an. It wu w.rit.t.en 1n 

eomaeatlon wt.th •ter1al u•ed tor educational pUl'poaee, and acme ot the 

phraetta in it reter to a particular a1tuat.1onJ neTert.heleea, it ia uiTen 

1D its ent.int7. 

•!11e danger to c17Ptognphio eecurit7 resulting rroa the 

inclusion ot srn~grshed addreaae1 and 111.gnat.ur•• in crnto11'1Ph1C meaeagulicom.es quite obviou• in the light ot solution 

'b.F the p1'0bable-'110rd method., To 1llust.rate,, retel"8Dco is mads 

to the 11esqge -.plo79d 1n Pars. 19-22, It w1ll 'be n:>ted in 

Par. 22b that. \he ••••a&• carried a 81gnature (Treer Col.) 

Ud that. th• lat.tel" •aa enciphered. S\l! poH that thta ••re an 

authorised praotioe, ud that flWert •••ac• could be uel.lliled 

t.o eon,c1u~e with a C17Ptographed e1gnature. The eignature 
REF ID:A71933 

"TJU..11 C.:>.t" would at once afford • ftey pod basis f Qr t.be 

qu:lok •olution or •ubaequent ... ae,g.. emanating trom the -- ~d-il.l.l.l't.81"8 .. did th• tlr•t. llMIHLl()1 'beet. .18• pr ... ...,,_1 t.bi• .. e ldp&tu.re would. ap;-•ar in ot.her •••ea&••· 

It. u tor We reaeon \h1Jt addl"•~•ea and •1gnat'.1rea 11U•t. 

DOt ~ crnto1raphedJ it t.hqaust. 'M included thq •hould 

be crn>to4raphed in a totall1 dlrrercnt. •Jst.• or b;y a whollJ 

Alterent. 11!1.ethod, perhaps by aeans ot a special add1•eaa &!ld 

IS.gnat.ui .. code. lt would be be1t.., lDnver, t~ amit. all 

144"8•e~ and eipaturea, ud to let th• call ligna or the 

lu~adiJ.u.rl•r• eoncemed aleo conve1 theue part• of the aeaaage, 

lenl1t1 tho deliver7 to the addreaaee a matt.er tor local 

MUan.fl 

w. P. Prl.edman 

19311 Pace 43 Far 2S• 

llU.lt.arr C'"i·ptnnalyeia 

Part n 

%t. ..n1 be not" that lb-. Pl"J.edman bae oon•1d•red ;J poH1bllit.1e11 

(1) "ad.ctr.•••• and ~mt.urea 11Ust mt be Cl"JPtoaraphed" 

(2) •1.f t.he,r ll\ISt be 1ncludetJ they lllhould 'be crwtogr&pbG(\ !. !I. & 

tOtall.7 ditrerent •r•t.• or by a 'ffholl7 d.1.ftere.:it ir.:etbod" 

(J) •perhaps 1>)" aeans or a special a-!~es :md e!o;ature eoc!a• 

•re 1• .. 'Uld.venal analyei• pertect.l.y eppllcabla to th• problm or 

.noiphr.red retere.."'lcee. Thc1·e is ho'tr'eVttr• or.e more q,uesti:>n wtd.ch 111u11t 

be added to t.J1:>ee raiaed b7 'u.'r. Frledln&n, md tliat. i• the practiaa ,111 ty 

et puttlnc int~ ef !ect either one or more or the ' possibilities. 

tat "8 dltresa for a 90ment at t.l'ii• point to eDild.ne IOm.e of ·;.he 

aet.hoda i.hat ar. now bein& used b7 the enmcy- and b7 ua in an attca.=t. t-o 

1olft the probl• of enc1pherlni references. 

The Jeipwae F \o one extreme ir, the uee or ~al t!IU;lded ·~ en- ~. 

dphered routing•. addreaffa,, &rid •iariaturea, b7 provldlnJJ • .-epar.,te cod• . 'book tor .Uh or t.a.1e., ud a ••parate add1t.1Y• tor enciph~l'"ing th·• laat 

two. fhi• i• in addition to an.othttr code boolc and add1t1v• used on the 

eem 

-11-
REF ID:A71933 

text. ao.ever, nen with these precautions, there i• 11 certain portion 

of the reference• that auet. be buried in the text itself. Th• huri•d 

portion tonaist• or the or1g1.nat.1.ng ottice, the m•••ace number t;nd. J'&l"'t.1 

and the 45.atribut.ion ot the •s•&geJ and t.hese are ene?df'd and •a.ciphered .. b;J' the •ame .,..rt.em. as the text iteclt. It 111 this latter m.at.er~.al which 

provides mtey into the Jap ti-atfic. 

Pr.act.ic•'l17 ever.r Jap aeenge contain• llCl!le kind of rout.int= 1na1.ruction1 

and exteml\l e11aiphered address. On tho contrU"I', very tew Jap .aeasagee 

have extemal encdphe:r-..d aicnaturee. 

l'ith .frequent chance of code and addlt.1.Te boon 1n t.he ,prei;ent Jap 

Mthode, 1t 1• tar trom eaq to 80l'f'e the aternal enciphered atldreoeee 

Incl Id.pt.urea. 

Solution ot intemal reference• ln. Jap ussaees are cospar•.ti•el.7 eaaier .. 

!be Ce=ana uae internal enciphered :reterencea, in a ratheJ· 1110d.1.tied 

tuhion. 1hq leavo out wh.ltever ia mt abaolut.ly necesaaey, repending 

on call signa which chance dally to t-.amlsh addressee. 'l'he7 el•o at. time• 

use L,temal cover name or code names to dis~se addressee .-nd si1naturee. 

!'t-.!s ie not a frequent practice.. The mat hport.ant. 1"tdge intc German 

d:Splom.e.tic trattic ie the enciphered internal reterences which 1. euall.7 

occur 1n the opening ot the aessa.ge. 

'l'he 11. s. Jla'Yf hae attempted to llldt the length ot th• at•reotype 

prcV1ded b7 encipher.d internal reterenaea b,- iseuing a book of address 

and eignature abbreviations.13 

A\ CBI,, a kind ot oode d1rectoJ7 has been put into ettect tor lateral 

uae (iICPAil5-2). Tile d1rectoF/ u•es S letter 6rout-a c:Uled "internal 

t:Sih&t do 8l'!l ti.ti. Finne, Rasdana,_ Sndes• P"rench do? 

~~_:_ ________________ llllliiiil .. liiiiiiiiiiiiiiiiiiiiiii-·iiiiiiiiiim .. mxiiiiiiiii_ ... 
REF ID:A71933 

address indicators• or 11desipators• t•:> replace add.res.Jes and G.1naturea. 

It i• witort.una.tei, not constr-'6cted tr:a a 2 letter dlt/'erentJal peri-

•tation c.'1&rt, 80 t."aat t.r.e.re i• a possibility or ditr!t:-ulty wit.l. 1e.rtles .. 

'1'he ustan."llent. ot va.l~e 1n the directo:ey is ba~ed on tne ottici1.l 

designation of a unit., since - as •lated in il"'A?..:": - gea,traphlc:J. 

location& and ,peraonnel change, but the ottioi~-1 deeien•it.1.::m ot a UDit 

Hldam. cban,g~a. BICr .U'"?S co."'ltendo th6.t the internal add1 .. 11c ineine.to:rs 

are UCUr.&te1 Ofter Cr)'ptograpt.ic eecuity1 and re4ucc tl~e 't1mc of 

-Ba&• propa.ra.tion md tn.ms.id•sioc. Pollowine ars 2 exampleea 

(l) PAlill CRPLA CAB Cuc aerial no.) PD: CA1'.AH J:ilAKElf 

(Signal Officer Anq Air Forces Ho. __ tt1am Comandlng 

· deneral AAF, CBI} 

(2) ACTitJ! Cll.\r.O en:-___ IJIP'O CTAAO .um CASA! :'ICM CPBDS 

(Aotion C.O. J{q• USAP-C!I ll"anch Hq•, l.5AP-CBI '--

Snto C. 9. IC'H.TC1 5tat1.on Mo. l, Calc;itta and 

...,.ndin,g &ell9"1 A~C tram C.G. 'Rr&ncb ~qa, US'1'-CM:) 

IICP~ contal..11s a e711tem.atic aengnrtont ot n.luea in "hi eh the f'iret 

Jt!.•ents ot the: codo 1.roup e'lneti t.11tAr & tricraph desi{.nating t'ha aain 

llaadquart.ers or unit and tl.lft laet t.., elftt.'lenta are a digraph d€s1gn&t1on 

•f a 1ub an!.t. Thia Jila:I' be desirable id.thin the local the6t.t.?r. It. 

l• quest1oriable T.tether this would bo dee1rab1 e tor \\Orld wide COlmlllntoation. 

In tho lig:ht o! t.he anal:r•i• ot J'a.rt. I and t.he 1tathods now being 

uaed, •bat. auagcstions cam be propceoc! to m.odit;r the present pre cedu.re 

in u. S., Anq'I •••• kee;>in:: in ml.r..d t.rAt whateYer le SQE'get'ltcd G'l.f!t inwl•• tee~niqu• that ue not alieri tC) U. s. UJ'Pto~rar,hf c procudure 

and ao .Ul n.:1t entail too .wich t.n1ning ot porsonnel. It. must. eut down 
_..... ....... -------------~-

REF ID:A71933 

th~ len&t.L ot nf•rencos u .much u possible. It. net be a ayatc 'l:!'dcb 

11111 dit.fer in •=• wq fl'CQ that used on the text pl ·o,tJer-. n rauA not 

ts!oder the pnparntion and t.nuieaission ot •••eagl!a. 

!hat \.he £enoral ru.l.ee ot econoiv r.1~ke tor c:17Ptogre.pt:ic •eoin•it,r 

la axlom.ttie. mus, it i• imperaUve to omit entirel1 wh~t. 1• not ab1oluteJ¥ 

necesea.r,y. Ir tho namo ?!SimJO;u.~:. Ot'cura 1n flt'eey e1ngle a-eseage eo:d.ng 

iaio WA!P froa *• ~rope!Ul .\r.a, it. i• 1UPertluous,, tor it oan be tsken 

for granted.. Uk•wise at.th QH~ S'.\T'..t. and 'ro Ml~\A'!? fro·~ the Sou.l'.hwe•t Pacilio. 

It chain ~tcornani1 routings are tl~• nor::.~ one•• they also can be taken 

tor c.r-anud. T'.:ie lnttmt or enciphered l"Olq instruct.ion• liq l1a 1.m;plicd.t 

.&bbreT!ations amuld be ueed wberev@r poaaible. The7 artr not cml.7 

econocl.cal but also ver-J d111concerUr..g to a crwt.anal: st as :1.113 one who 

baa wor~•d Jn the Ger:aa.n police cipher can testity. 

lri1reTer1 in addition to rules tor economy,, it 1a felt essential that 

ltOmft &ddi t1onal steps be taken to disguise the internal re!'erancea. 

It 1s borob:r prop:>sed t.hat. a special address ~ signat·..ire code 

d.irector,J be prepared and wsed in conjunction ldtll the a.we ll)'S"i• used 

to «to!pher the text proper. 

(l) Dl.rect.oey •l;0uld contain 5 elcnent groups baaed on a !! letter 

dlt.terential cl1art. 

(2) Consist ot ind.1.v1dua.l IJ'O'QPS tor high echelon 1.IDita. 

(3) Ch.-"t.a.ln croups ror 1000 ambers which can be ued in ·uu•ioua c:.ombimt.1on1 with ea.ch other tor 911eod1.ng internal m•SM&• numbers. 

(4) Contain individual groups tor mllt frequent. r;;>utJ.na•• 

(') Would be d1•tr.1but.ed bT 017Ptonet. holder.. E;ac:h holder would cet 

a leotlon of the -.ster code direct.o:r,y - that portion !>•rtaininc 

- 20 -

·--.~--·-- ·---......_._. __ , ~ . 
, 

REF ID:A71933 

t::I his usuiU e~annol:s :lf eo!!V:.'P>ii•.r:t..ti~n. Cert.::.in center• 

WO'Uld hold aever~l sectiona. 

(6) lli.ract.oroy 110uld be chone;ed at irregular- intcn<:t.la. 

(?) Uso or sped.al addro•• and si!f',e.tu2-c code direet":)cy- i.:a not 

.attdat,:>r7. tr no cede group eJd sts :or a p&rt.1 eu.lar md t ·>r 

MtJ.tinc, or if tbc code directo:r'l.- is not. a•a.1labl11, tho pract.ice 

1ICtft in use C3n 'be tollowod. T'arti~l coding,. aloe.,. le pel"-

.S..111f•1e. 

tt ldll bn s11ien th1;.t thesr. sUKaestions a:re but expan!!on:!I on tf1 • 

Priedr.:r..n• a idet~ thnt a apecitl address ane signntur,_, code ho ueed. 

The pn.ctic~!li l1t:r ot a special. a<!dnH anti •icnatnre code dircictor"T 

S.s cni.dmced llJ' !TCT'A.T!.fl llhicb ls nvw 1n u111e !vl" la\.eral c<1•n·.lld.catic•n wit.bin 

CB?. tt&port.9 indic:o.;.t.e t.hat. it 111 tee.sibl•. It a. dli:·t.ctol""J cu. be used in 

lower ec'tielor.w, it car. be used in higher c-ehe1o.,s. .\ direct:»J'J' of .a.bbre-

'Yiations n'lw 1n ua• b7 the U. s. "'•V)" dcm:onstr.t.tes pract!e4.biltt7 wt' an 

extra 'boat. 4 trped.Rl t.ele,h?Tie dlreeto17 h&s long been c JnYention il Jn 

th• 'U. s. Ar.rr;;. 'o the id.ea ot an addroaa &lld s!gn=.ture book i• qulte in 

11.ne with .O. ~. proce:!l.lre. 

11buld. thE' \Ille Of & special si&nat.~u &Ud ~SG directo17 hinder the 

preparation and tr.ttnmi "Jsion or 11ea::>agee? 

~ \ha contra17 althoueh extra t1111e woult! be irm>lT•c! in the u1cod1.n,c 

ad decodin~ J>r.>ee.!ls, the time ot enc!pherin.~ and tranaml"',ting mesf•a&•• 

wonld be cut down Id.nee entl:re rout.1.nfs 1i0uld fr.etluent.l;r he oonden·•ed into 

a 1111161• ' letter gTOup. 

Ia \he us~ or a llJ:ccie.1 addrfl:;e ~.d a1gnat.ure d1recto17 ceyptf>graphicall1' 

•re HC•ll'O ttian tho present. pr.ii.ctiee':' 

l!C!B'.l' 

.. 11 -
REF ID:A71933 

'Ihle que.t.lon will be con.S.dered in the li&ht. of abili t.7 to IM .ke 

deduct.ion• from• eorrelat.ion ot external features ot the tramaitt;ed 

tom ot t.he •••ai• to t.he enclphered .5!2!l!. nrennce11. 

(1) Plain text 110rd uam1ptiona would be ut.t•rl7 1n•alid. 

(2) It la ftJ7 llkel.7 that atereot.ne internal aipaturea an·! 

..tdre•e•• in the fora of eoda iroupa 'llll1 cont!:nue to exlat.J 

l:fu.t. 1 t would be hipo1ud.ble to make eorrelationa betnen ezt.emal. 

e'haract.er!.aUca and the code croups unleea aan;y aesaagea are 

I01ved and the direct.o17 reconet.ructed or the cl1rectaey captured 

tnd. camproalaed. The toraer ia not easy deapit4 the le.ct t'hat. 

dlrect.o17 groups will. be 'built. on a t.wo letter ditterenUal 

bas1•J the latter is not too probable for blah echelon rnanters • 

.A19o1 auceeeding edition• ot the d1recto17 are contemplated. 

!be use or a einale code group for an entire rout~ will maHe 

nterencee abort.el"' and pro'l'ide le•• cipher text on which to work, l>eaidee 

ott•rinl: the handicap ot a code. 

M tur lntern&l. number•• - They will be repre•ented b7 eode 1roupa • 

lloweYer, an additional cr·ange 1n procedul'e i• advoc&.t.edJ that number 

iei'!.u at.art. 0ver again at irregular pe1"1.ode and not run conaecutlYelT 

.. 

tR ID entire year. Thi• wUl obstriJ.ct tho abilit7 to UM •n:t n.ullber 1roupa 

that..,- have bem &K>lYed 'b7' tll8IV c17Ptanal.7eta. 

lt MT or Ml" not be nec••Nl".Y to use arome a.thod ot ieolat.Jna the 

code retenmce• trma t.he text proper. It necessaey it ia •ugges1 ed that 

the uee ot '-'IU!ll 'be di•continued. The ue of I as a uniYeraal p\.nctuation 

a1gn ueed b7 the layY is an al.tematiTeJ or perhaps it 111&7 be advisable to 

QQ 

u•e 2 l.t.ter •epan.ton in which cue n, n or tz aould be uaed in 11111' 

Q QQ Q ~ 

COflbinationJ UI JZ - n, ll - ZZ1 ?Z - Zit et.c. 

IKlii!f 

... 12. ... 

- - -::J.":. -r:::. -· -- ,.- - • - t' 
·saem 

REF _ID :A71933 

These s~•plea are t.alen from uctual 

tr1;.ftic. Cnl1 the spac:U'ic r:waberinr. aarie• 

h::Ytt been changea uo •• not t.o t~1ve nwal;;er.s 

ot actual •eDL'lhG•; tho order Di roni 1a 

aut:ber&t1c. Poe1t10l\I. ot tbeae 1nJert1ona 

are !•1"11' wll vacr-1ad, t.haullb ti.re 1• a 

tandcc,- to pl11c• tb• towarcl ta bag1aaia, 

ot tbe MNa&• .. 
Ilea! nos &OD'thlft PJ.CIFIC J.RKA 

I 

PA.ltD CJWtLIB !WO Tf.O PIYB S&VU zao FRO• OHQ SIP.A. SGD IUCAJmmB to CHiil' or STAP'I' 1'.ll 

DEPA.RTJIEH! PA.REI PA.REl~ TCI CHil;F Cir S~A.FF ;'..,R DEPARTi~M FB.OM !!A.Cil'rlUR Cil/LRLli TIC TWO FIVI SEVU 011 .~tinning ot ug/ F~~ou GHq S"IP.A. SOD llC.lRTHUR CEllU.n: DAY T:iO BO FIYK SIVEI no !O 

a.OllA.H l!lr\, 1,i•.: ·.;,;:;::l:'!t!O! 

PARFJi CP..lt.lti,I& TWO Tl'i'O FIVi:: Si::VEJ1 SIX Ji'flCI GJiQ $J\.r'a i:>\iZ :~c~~!'?-m.R 'rf1 A.GIJ.R .?ARU 

QQQQQ J:1?.01l GR~ Slf PA tOD iACAilTHUR TO .1.G\\'AR IJllPO TO A.TC WASRlJIQTOI CHARLIB X1t1"X tiaCi :i:'iC 

FIVb SafBR ElCtt~ PD p~ CUAllLI~~ :-~:o r.;o F'~Vi:: ~irV~- lHZ.:~ ~·on IIGLL:; FROM AKIN PAREI PtaRi.!;N RKORAJ> "'], lLLIAJI 

I-'OU.3 f. r:: Olt i"OUJii ,,Hi 't?:UUiL St\"~.NTH !:AY CITfS ~PSOT tAR.t2 

Pila liilR OBOE i'6l~Tr!R DOG PARt.Ji J>ARl.fi Tu .&.01iJ~tt Pl101! l!lCi i<THlJit Cli&RLIB. ?1'10 T:~o f.'IVE 11cm 

Zla\O .1J hlUUi 

PARK~ POR onoE Z:1.:Tl!l DCG i'~lBEI CJ~LIE r.~·c.. n;o FIV~ ilGli? C~iB FROI OHQ UfiPA r.GD IA.CARfftl1R 

TO li.G' .1 1~ PD 

PAlWI J1'R01.T OH1, S';Jf=i SIGl&I> ltA.CJ~R~lltJR 'rO AGt'1AR CJii.RLlt T'ffO ~c Ii>IV}; EIGHT rmu::c PA.RF.JI 

PilU FHOV f:ACAHTHUft GHq f'f,'?A CH."l.RLU: XRAY n:o l'!,•IJ l"I'll~ !f lUS 7.KnO TO l•G11i1R lJIFO ATC 

f.ASHINGTON YOUR WILLIA!'. l"OUR FOUR PIV'"'c; m~Vl';N OM& ?.lR.L"N 

PillU C!LtRLlE T"-~C TfiO FIVE IIIE ON& FROJI Jlft.CABTHUH GHQ S'IJJ.A TO CJfilsF 01'"' ST.Iii.FF 1''1.R 

ugPARtJjJI'! PARU 

/be11nn1ng of f'.Sg/ li'ROf~ cm~ S'f PJI. :JGD J'-.C .. HTli'On ~B.':.RLI-& "" TWC li'IVE If IJfR FvUn TO 1i.G1~Ut 

m,v1.;u~1:c!; !OOH ~ILLL\~~ l.RAI TlfRJ~·~ TJm£E Sii SII FOOR APRIL SIXTL.~H7H AJ:D 1'ILLU.I 

FOU=t FIVJ: ZERO Sl!.VEl4 lUGH1.: l'AY ELI5Vl.;t~TH 11l 

PARDI Bv•J!~ UIZJ!;AQI A.G'lflt.!l CG DECkL CC "tt.,~lSC& CG A?lllDEL CG SO'O?AC CJ CRITP&C UlLITARY 

ATfAClfio. LONDON FFiOl' GBte Gf1Pia SOD :u.\Cl .. RTliUR CH.A.RLii. lRAY no rvro FI'lt; HID S&VU !'ARD 

PAJlllf 1'0?Sl•;(! l'ROl~ GJf 1' &f.'PA SIGJJW UCARTJIUR ro Cf1ll.F 011' ST•Ff t.AR DEPARXD.lft FOR IARStiLL 

lrR ::itnnLIE TWO nm !'IVE IIIE III~ ?ARKI 

Pila CRi.RLIE T\70 n.o t IX OJE EIGHT FROM GB~ SWi>£. Tti CJaLF OF STAFF \h.R D6i'<BI! PA.RU 

OtBIU.1'ICfiO Rli'ORT ~O'J:~PAC J.REA PLJl.IOD 1400z/l5 TO 1400&/16 SIGIW B.CARTHUB PD 

PBOM GHQ SWPA &GD w~ca.n:mm TO CHIU' 011 S!lFF WAR D&PAJlTIEft PBRSONAL POil llARBHlLL 

CBA.RLIE Tfi:O no Gll. r·o ZERO f'ABEI 

PAID CBM\LI~ '1'1f0 ft'O a.1:( T:fo 'l'IRU FROlf "ACA.RTHUB. OBQ Sl'Pj, TO CHllJ' OF at.alP 11A83IIOro1 

00 PARIN 

PAUi CtU..!tLir; XRAY r::c no .:.1x nc ~!JiVE!I CY:.l FROll' Gli~· twPA DOD JWaBTIUB TU .AOWAB l'OR 

ACTION TO COilGli:IGOP.&.C ~CRGJr;?\CKIP1t.C FDR DIJi'O!JIAflOJl P&RD 

ftlUJW) PJ.'?1 ~ERO POUR no FIVJ;; DllfED Ol'JI FIVt KAY Olt KIIJ; FOUR FOUft PAm;JI FROI GHQ SWPA. SOD 

lU.CAR!mrR TO COllGU USAFICP! roR RY.A.If ia.C!lOlf /,f}'r AR INFO CJIARLII XRAY TWO no s Il 

TlfREi. SIX PARSI 

PAUi }'ROI! GHQ SWPA CHiLILU: no TWO SIX TIREE 1;1on 1'0 CHIEF SIGIAL OrFlCKll WAIJBIIG!OI D c 

FOR GEIDlL IIGLID no• OBDlllL illl PARlll 

-1-
I' 

.. 

REF ID:A71933 

\ . no• SOUTBllST PACIFIC lRF..l 

FROI NORTH AFRICAN ARl~A 

PADEi 110X Gl:Vt:\ FOUit ZERC ~Ulm l~lGRT ClGllr. Dt:fi.!'lt ClTB IAGAf' 1-'&Hhl 

PAIWI r:oox SSVtr.N FCtJR Ztftc. NINI l:Jli: SlGN1.D DEVMts CITB NA.AOI TO ACl'.l.ll Pa.HU 

PA.BU FO:~ SEVEN FOUR cm.i. Zl~RC TJUlliE f IGJLD DEVERS CITE IAAGI!: TO AG'llAR Pa.RU 

PAR.EB r·ox SEVJ;~~ FOUR om~ ZERO PI\i:l~ f IGJll;D DEVERS c IXB ltAAGE ro J.GWAR P&Rltl 

Pi.BI:I FOY. SEVl.:.11 FOUR mu; :lERC SIX SlGlkJ> ).)J:.VEitfi cr.n~ 1.AAC': TO AQf.Il.R PABll 

P.A.Rll li'OX ntvr.N FOUR om: 'rJDU~~ mo tIGRBD WILSOt~ CI'r& l'JlblG TO 'Gt\'lR IPOR Ullill\iR POB 

LOP£Jii t'nftEll 

PARilt POX BKVU.N PtlUJ\ mu; TURii& TllRlUi SIGIED 1'11.SOI CIT& r"DIO TO AG"AR FOR ilODEEB 

rem ARJ!.Y L:.t? SillVICI Pa.REI 

J>IJ\£11 CIGl£;D Dfft..Q\3 CI!£ JlAG/.P FOX r.&Vl~H DUR ODE !HJll:J& 11111 PA.Bii . , PARF.I FOX Slm'.R FOUR OJI& t'OUJt Zm\O f~IGJIED DINKRS CI!li RA.AH to AGi";!I l'OB CIPIOI AID P.m 

.f'1tlS0}1EJ\ CF ~UJt IHPOUJ&\.:lUJ1 BEt~U PAltBI 

PABEi i·iO.I SL"VJ;lt FOUR ORE IPOUR Olm :·IQ!fl!.D DEVI~ CITE ltAl\GI~; TO ttOV.'1 R i:·All&B 

PABEI fOX L1EVJli l'Otm Olli l-\tfJUH !RBEE SIOIBJ.> DBVBHB Cl!I HAAGE 70 MiW4.R PARD 

PAIU POX S&VJlf JICUJ't OBI FIVll OKI TO lGWiR FOR CCS IOR CCA.C RIPIA! Ull10R &ICD.D III.SOI CID. 

FOR EIT!.81 CHIUS or,,,,,, rDG8 

... 2 -
I 

r . I 

I 

J_ 

·--

1 

REF ID:A71933 

P'itOI IORTJI APRICU iRtl 

Pilll 1-llX. SEY1'N FCUR ON~ PIVt; FIVE BIG!ff ... D DliV'l;at, CITE Ju.GAP 

P411lf .U.I ron cso TiOOPE.R& l'Ot! SIGG S&Vlilll A AG'fWA:t Cl!t SPSOL 7!ill' POR Aill SIGl!L Off'ICD 

II CH:I~P ~ID U6% li'OH SlG6 FlU)JS Al'IQ errs 1'.liSIG FOX SKVU FOUR Ont GIX FOUI Oli SEVll •.&I l~".!! J-'('II O&VEll J'OUii Olft EIOM ZUlO PWI TO Oil SIGIED ":\'l!.301 Clll FllPSO .lLl.AE OD SEVEI 

1 IHii. ~nru:a.: mao r'niii 

PA.Ult FOX szvr;;r POUi\ en~ rnN& FOUrt TO AOViAn l"C:i SUR.II~.: ~lC'14:.:J ~!!.SO!' ~!TU nu.IC .i'&RU 

PARE.ff GIGJIED DftV~nt CITI JU.TPff ro A.Q'ftsjB FO.R A:!ICK TO CG 806 !tiTOUS.l J.JiD co mis u~:rott.fl.AiIGii vr_'1 l"!·~p.· 'r.•I'·"" ,,,..,.f' zr-·t>o .,,.IVr. . DIJl11f &v~ .. ...,: ... r ..... ,-...,t.JI .... "'~ "- ~ J • T.&ln1111t1 

i1.liil ~·~x ~;zr~:·~ ft';l F. 1~0 Tl\C FCUH TO lG'··~n- :f.'C!~ ccs 1•.iR CCAC RP1'D U:TliUSi~ roa BCS SIGRID 

t'iILSOI c IT• n:nG~ i'AREI 

PAlUWi FOX Gl~VL • FOtR Ofll. PIV~ Zti;H( TCl S.G····~Il t'ON CCG A!:D CCAC lWlD u.a;:·o;. l"O;t I!Ct GIGIED 

WILSON Cl'I'E Jii:mc;s PD THIS lf LOVI:; kBL& CDllRLIE Jt·oua ZERC TlC PiLlilm 

RKFlllf.HC& otm ?'.46725 OP 16 IA.I (.) r·ox SI;Viaf POUR TT·O 4~1~RO St:V15 TO AG'fJAH FOR ccs, USFOB 

PARF.n rg~T~~; :g~~fii i~~~,,s~~~' n~ ~o~~~~R I!~~~~~:~ ~g· A=~=l'OJW.tIOI 00 CBI PARU 

I. SIO?IED WILSON Cr.ti P'llOR.B FOX S!iVU roun !WO 81£YkN Tll'O. AF'BQ FOH AC!lOI Ill.STU 'IASHJ?IGTO:I 

PRCV l!OUITFOHD F'CR P..At~Y I. 

x (FOX C!.'V!;Ji i'OUH 'f~;o ~IGilT CIX) ACTIOI AG~l.n ... H SHI111'IIG /1.0llIHISTltA'tIOI FOtt GA.DDESi cxa1;m 

'· 1L801i CITt Ik:..I.OCH N11as 32.3 x 

Ml'.S 324 m~Pb1t1'C& '

1 l,;NA 767 l(FOl Sl:~V~N tOLh ~70 i:IGR:' 5f~!Llf) l\CTION A.Q.fi~R rort G•Ulllt~ ':IAR 

ZllIP::>ItlG ADl!IlflSTRhTlOI t.\S!lIJiGTClf SIGl&l> tILSOll c rra KALLOCH 

X (•OX imV6li FOUil Tr.O EICHT r .. IGllT) &CTJ(;l'I H.01Tdt FC1l GILL}l;Sl'II!. lllEJtlCA' EXPOM' LIDS 2S BROAD~AI llC1'; YOHK CIOHJ!:D r:ll..SOfJ Cl~I :ULLOOB 1 

X (POX Si.VEN FOUR TWO ~.IGHT ~IIE) ACTlul\ A.Ul nll F;)!i G!LLl;Bl>ll lJli:RlCA.f~ Jal'ORT Lllli.S 2; 

BftOADlfiAY Jr;l' YOU: SIGIKD f"ILSOI Clth ULLOCH l 

1 (FOX ti~"Vf::I ii'GOH T'~O J\Ilt Olli) AC!IOI •OWll\ 11AR SHIPPIIO WKIJIISTRA!IOI .io"OR COJWAI SIQISD 

1'ILSOfl CITE IALLOCB 11'"''6 3U X 

1 (P'OX Si~V&N roun THRl!.I~ n;o Gll) .TO AO't'AR errs IAAGO SIGJfi~D DIVERS l 

1 (JPOl StlE!i l'OtJa THJU.E TtmtR TWO) ACTIOI lGfiaR PASE TO A.lfPB POR LIEUtlf,JIA.llT COJ.OllL IORGAI 

C I?E l•'HPET D ICllI.:J i; ILSOI X 

PARIN re AGl':1,R !:C· Gt)OROC ll'OR IHELiifiD 1)iSD TC SUllL!!.S J.'ROll J~.AUCH SIGJmn WILSOI FOX SEVlll 

J'C.UR THREE THftlE FiEVU P4Rll 

PARll.ff !''OX Sii:V&ll lotm Tfli~B ruRJ,t. llIGIT FROl: Gl'I'flU. 10R BISS&l.L SIGllID Ill.SCI rJ&.lUUI 

P.ARU (POX SEVIJi FOFJH fllbl:. fOUB 1111) l'BOV SAf:llIDGK SIIJDI> -D&VIBS CI!I IAG"P !O A.QIU 

PIRIOl&L FOB Wltl'?lt .PAMI 

FROJ( aJROPIA.11 jRJU. 

PD ron SPF~ RUJRA: Tr•R NO EIGHT FOUR S.&fl11 IIlfl PROI COBBS 308FD r3IGlfl:O »IBEIBOllD 

IA.St &lGHT no .no FIV~ OB PD 

-3-

-' ~ ' 
REF ID:A71933 

6dClti'i 

PBD FOR SPPICR PROll COIBS 80SFD S GOD B!SDBORR EASY IIGll'J.' ftO TWO f'TVI ZC:RO POD 

PAID POlt SCJlllBV1U.L FRO!' ID StGDD IISDHOUB U8Y ilOB.T tfWO 'r'IO PTVI no P.utll 

.PABJ nm LU STOUD StSBlltORR US'T BlGBT TIO HO rtva 81:'1D PA.DI 

PD TO mn FROll I.KE $!<RIED BlRIBOlrllR EASY EIGft no TWO S!J ZERO PD 

~!!IR!' ,,,., kUI. F'BOS r..BE sronD EISDBOWD EJ.IY ITGHT flO no St.I zmo PAID 

P.AIK'I FOR SPSRB POR ca A.;;F ~R : tt••~nA"i i01. Ji:&\;;;;, r~;: lUU.?!' !'!!6'! !W:fl .. "'* I.a: ataao 

'l!SDBOER 11.A3Y IIIlft ffO TWO STX OJilt PAHi 

l.&DI IJGIF.D ETSKDOIP.P EAST J:TGH'l' Tl1f0 no ssva ZERO PA.RD 

'PD l70ll SPUR sramw ETSJP,tflOIER us·· E!GllT ftO 1."IO SlftS on PD 

l'D FOB. sw1~1r fROll C1B!S nOSPti STORD ITSllHOIER EASY RTOHT tttto SEVU TWUi' PD 

PD bSY !TGHT TWO TWO sevn FOUi PROlf LD STOIHD B!!llfBOUB PD 

PD TO IJntOtl' PR~ AP.Allft UST ETOH'f Tl'O TWO StrVD F'TVK S'T'OIRD BtSDKOIER PD 

PAnl Pf'OM DOOLTftI.F. !'O Al'J!OLD PllOll SPAATZ ('!AST rrom TWO no ltMCJ SIGB'T) STOD'ID ZI~ 

•-Olll.'I RIPJtRDCE WAR:J T!mBE DP-0 T1iBD Uftl YJVE IUY FmST PARBI 

J>.ARWI Pon SPP.&ff. Pf'O:..' COBBS S!OIED J:IS")IJ!ORR EASY ETCnrr TWO Tl'O 8011 •rn ISOSPI> Pd'D 

l'AR!I STOIED IIS~JllEOll!R lift' KIO-P.r no ftO Eton on PABD 

PAID ron SOMllVELL POT{ tft!OlORY FR<m :r.n s YOllJ> BISllBORR IA.IT DAY TWO BIQBT TIO :non 

tmm;;-- PA.RD 

PAID S!f>Jral) BlSBJlflO•~m P..ASY i!GRr uo TWO EIGF.T ?I\~ PARDI 

Pdll cm SOSOD PHOI L'BB BiiJ?EREICE R'Oll~ ~AS'! 'IDAY 'I'WO RTOST TIO FtOJIT S!OIBD BIBJm. 

IOWBH RIPERRICR TOVB 'III.LUM A.BL& lOOBR TllBIE SKVD POUi! WT1IR FIB PA.Riii 

PAlttlf STOJ.'Bl> E!BUHaitlll US'f Jr.IOHT TWO '1'110 JttOA'T SEVIJI P!RD 

P.ARD Sftlw.D STSDKOllR B.ASY URAT znnrr ftC'I TIO SIGft •rn PARD 

P.&BEI TO TNGLBS FOR srsco DASJ! L '1'l~ca Lii t11Tilntl JITSDBOWD BAST lWUY ETQH! TWO ftO III& 

ZIBO CIT! SOSBC 

PD ?ROll U!E SIGDD ETSDJIOUI U8Y UJUY ElCllT WO TWO :IIJE TIO Pll 

P.&1111 TO OOMPP.VU:LL FOB econ rium Lr.a 11Hlf> ITSilJRllD l.ASY JWUT lUOH'f TIO TWO JflD T'W 

CI'l'B ETOCE PA.REI 

mm R1JllOTfOH PfilOI ~ (BUT DRAY ITGIT no TIO tn1fE FOUR) SGT> JtSUHOBR Cift aossc 

!O SPSAS 

PAftD P'OR S.PXPR E'TOIP!D BTSEIBOmt •AS'-' ITGHT no ftO Ji!& PIVK P.&nn 

,.._ !UP.llTOI TO ltRIOll> P'Cll Lr:.tCB CBThll' OPUUTIOE AlfllLT!ll DmBIOI rOR 8PAAft 8TGDD 

E!GEDOWER (EASY IItlBT TWO STD ZRBO $TX) PJJID 

?ARD SPU'l'Z Ctt'E IASY Jt:tO-lfl' 'rSO ftO 1fTWE !;TGB'f 'I'O m,ro JYO co MP SOD KTSilBOWIB Pl.fill 

PJBD TO DUllLOP SPGAR I'IPO AJUIOLD J'HOI! SP.UH CI'l'I EASY EIGBT TWO TWO IDJS JltD ltGDJ> 

ltIBDHOU1l C!!W WAH 'HO SZVl!1I '.C011T TWO ZERO URCH no 'ITIK PAftBll 

P.llft TO MaOLD ~ SPAAD STOJrBD XISllBOW!ft Oift BA.SY mid! WO fliJtU ZDO mo Ii.AU 

l'J!ftXB STX no OJE on BT THJ!l!l'!I P.lRD 

PMll FOh GROllIWGll TIPO tlt!LaD Plot~ r.rz STGDD K'J'SJIDORR REF •o UST D.lY BI8BT ftO 

tilllll J'01l1 SIX PARBll C&Bt.I WAR ftC) 'IDS ltll l?D raR. DA'lD f'Oll Jl&Y PD 
0:111 

PAID 02 DI. !LY C ABLK DY T'IElft IEVSXTH IIOft ZEBC ZERO 1'0 WI$BI PBOS .,.BI Flif.W COIUJ> 

Slft!D KAST EIGHT HO HUB Ptn ftO ~ PAP.II 

P.t.R.11 CID ~osm l!D TWO Frtt PC>11R J'llOll ROIJtl PROW LD SIIDD II8UBOUB USY KIOm 

'J.'WO TBREB FIVE J'IYE PAB!.X 

PD Ctft SOS'l'C !lil"ll OD PITI! PJVE PBOR ROSS FR09 f.D STIJllD lllSll!IOUR R81' Ill U8Y UOBT 

Tt-tJ Tiii~i: !!.! 7 !PO ( IY PAIS TO OSJ>) PD 

PAID CTft SOS!C lll'.IE Olii FtVE Sl!."VIJJ ~iiJii I;'~ P•'-'f r.n SJ'0.111) B'ISERODR usr JJUY EICHl'l' 

TWO TllR!F. srx OJD. PAF.zt 

PAIF..S !'.A8J EIGBT 'NO f"i;ur s~x TliO t'O BUlU.18 PROI LA.REIC'.B ITGBD JUUD(9D RdB fAR Jl'GUI 

Fnn '1'110 DRO lllB rARD 

Jt.ABEI £ASr !'IOr1? ~\iC FNm NO ! ... X ?OR ~PX?R STOISD K'IlllB~ ~AJlD 

Nim POI OROl!lrrllB. PROS LU ltfBllD n bi' • Bldl'I' umn ftO f'OUR POIR mo to 

car •.a.a o cas w 1J0L a a 8IU1I .. .._ 

-n-
REF ID:A71933 

DVY SftLB 

PROK COIDff'.SLAH .lCTTOI C'r.F srx f OlJR ARD CTC TIO ftO t'lOT FOUi nro CIICI.AM' 

L\&.58ITT Of FIRS COllS.LKVD 

x GRtr~t• Uiir~:~ti'C~ r~~IP'!!fn r 

x S.ATS {'OftASTSli AFROS Jm>TS OJIE rovn ZDO SIJ :ruiu.11ow l: 

x •AV! YABI" 1:n YORK HAS FOH .ACTIOI 3HJ"l PASS TO CRAftL'IE If.ARB FOX srx SIX FOR llFCi x 

.x &mB c~·· ~ DE nrsi.nmsnra Ol'F'Y'CE TIEW Y<EI WITH CTS ft() ZBRC on Pt'VE 'J.'10 1'0Ult :I 

:x 8Bl't' !!' C11ICLAti'f .AC'?ItJB TAS1< JPORCE5 SIX RTCH'r STX FOOR srx ftRD SIX no COllalRVLdf 

POX .AftF 080!3 1<'1 BOO':Wll llKVl YOPJC AJff; CPi!~T1Lcrrol X 

X UT! P'frOM C!lfCLAft ACT!OI OFF' TWO POOR Il'FO CODAY111J X 

XCODAVJIAWRUfiCT PBIRBCI '

1

Clrrl.EEBOIT<I frn'ULV!.1«.mmnmlt 

X COIDRSLOT TILL!WO ACTIOI DUPERS 'RPO Om:uft X 

:t TJBIO ntTLA STifGS X 

X BAIOOOCK SPri#ItF AOf! JI C:IIOPJC RDO WABBI PAIS tfO JISD 8JBBTC8Bftll X 

~ SAT'S C'l'U ZERO TWO Porrr 1nm !XllffJKI J. 

EmlflIPS SLIPS HIS OJ'iR OUT TO JISD ORQ 

ntr!HD'S SI'lilS '1'0 R.AI! 080& BHD 'IQlFOLI 

IWU' .AC!HOtl't'smt.A I ·CORfS 

CCllIJ'CK. ?ELLS TO CDCPAC x U'a om !NO zir.no SIVER FOUlt TWO x 

X..At.SIVJl:CBTIS!GICOBPIAJU.X 

ecm:ARTillUPltO• ~.AIBB illmAT PLBABlll D Plf EB&IJ!'IIO BIB wan JIU1IUG) POI 

-6-

' ' 
j ' 

REF ID:A71933 

aam 

lill'IISH ~TYLK ( f!1I .J) 

( (( .l!Rllt! ft.ALL At.l~AH :·'RO$: HQ JIAAP. API08(809 8(8 JIAT. ED .AI.t.YID £IR PORCll ann Ml~~ ""fl.. 1p;DT'l'PJU1.ll'll 111 ALL IJlD ) )) 

( ( ( A!H MJlirS~ l1fft•?!!lf.&!L /I. -~u fiiUii i1.;, r.a~ .~~· .... ~!..!" ~I)'.': tt3'7(U7 15/5(14/f, SIC:fl!e'f. 

5(!7'Cl'fF.P.H,1··~ Al l.I,LIT1' ATP F~Rcr.s OPSUll t48("8 jl£i COITlWA'l.TOI~ OF Al!LI'! l"OJ. "'"'TM· ~i~T'I'' r·? •· :Sii f.T,:O!r'D i:~,~.CTTCJ.L I\ '11' POf'CE'. ('O!FECT'rCI OPIO M'i( M7. AMlilD ) ) ) 

PAM rrvr ,':tit Fili/ L P>.1 ''t' ~ A!Il' ~ox NO( :atri 16( 18 V.'. 

(( ( il.l j~iWA>" l "f:Cfi ·~Q'~'A!.~· ,ty;; ~'1( 3,1 1,f &l'f'H "Lit' 81Ctfll'I'. TUllt'ran.. . ;f!£r.;TTlfW ,,,;ru~ .&LLB» 

11tn p.-·pc£!! o~stM 661(061 l)) ( u "'' Anl!~r I"f~Ofl ~1~ ...... r APMl(ZU l.i(li' lt!!' Bf'CRE'? •.rrTIJU,AHli.U: Af.LIIO AIR P"<mca OPStnK 

l.&SU f·fi2 l.f ~ Sf.P ( r· ASI P' • 

{ ( PIP 'l'Y"' ·~~ ADLr' P'01. trrr~: PC·Tm '!'JIJ:..,,U. Y..'t'Gl_;Tf ;·1'ft •AT 81Clft )) 

( J:Aft'J.' ST}: ff•l FfJfAI. I'-" ·f~4S(NS 181811(101912 B F'ft'OM HQ •UY) 

0.4811(0.4811 TC COS"''rTIZTl-'U' lt·r aI'SSfTS (Prlt~l'.:'O~A PltS C II C lllD ALG:rtm:; dtD '1(7) I.DY. 

!11!!T ( !'fj':"J'} PAS'"! f:Jf~R !'AC AX,f'(' R At:o 8(1) 1'AC Aii l'Ofl'CI) ru·o 8(2) DTS~R '~T (FASS 

lf»(l& tTP. PN~CB {~) DJ~TRTCf (1) ;. 1.:H'RTC't PRa.: IQ. lf.T SJGllD WtLSOJi C!TK FllC!(GCT) 

1"SJCTC'1CT) .P.Jlll l"tlGBT(J&T) WAY 16181&. lS =' Pli."l. COSJ1't11TRU 10. tll(fll) to J.IOO(J.800J 

r.P.8 115( 1£) Ml\". f'jt\T oa. !ltC"T" °" ""' . Tl!ltU:.t!JllCE. 

aacarr. TBT:--;- c 'Plra.R PART CF llQ ''t(AIJ) CO~HfTITRU.P llJl'aft t18f 63.I) l"r':kalO CHIO rm01819 f 4629 l • 

UD OP PAJ.T f~T X ·1P Nlll1l!KR 04889( '8•) OJI' COi.; 'fTK1'R5lP nl.lllt Ill( tUI l '1D10(l 'JBllO) PA.llf 

81:\ff,lt Al: V t.A: ·.I' POUtOllS 

8t:\'lft1! CfPfWJ PART OF COStftn'R.IP IUKstll 411(•11) SRCRb.'t' P1~0lr HQ AAT(AAT} c&IO lff.1KefCI 

ot81D( '89&) Tf1RU: EIDI. STIDD IIr..8011 C:'l"R PJlllCT(OCT) A11D PJl!OHT{OBl). &i:CTIOI 

o ...... ('831) 1881ZOC1:-•a..~30 B FRml AAI{AAI) ·ro CCBY'f IR.A81j" 1'1.;AD 'lO coaml'l'R&P AlJl'IUi&&ml. 

AnQ (,,Be c ,.., •&o ALGIRI.$) nt:tft' (ll!AIP) ( P.ASI F..IPM TAC IJPOR f.ID (8) T.ICftC.&L 

An- P 'RCI T."1'0 8(9) DT&ft!C'r (T~ABB l.lfll' ATII PORCE} lf3) D?SDtot' 1(1) DIStRtCT 

(PM.a .,<.,I lf'7ti."'V"}. amna nrLSm: crm PIDOf Ar.I> Pf.Im. Slam'. amrTlllRl!P •W 

tlf(41'' 'TO 1800(18(0) 1U U(lB) UJ. l'A\lt OllS. 8CftOS om • ... D',...1..,1 A• t.Aft C!l8R Nm ti' C09TYlllDD IUJlllllH 4U(IU) PRllll 8' AAt 

-..... ........ _____________ ~ 
·------------- _llEF ID:A71933 

·~ .... 

mmn 11 

rD.I DA'l'l/mo: 

The tile dat~/t.ime ll'OUJ> which llppears a clear ln the preamble 

Df ••••ac•e usually' a!gnitiee the date and time put on 1:Qr' the mter upon 

tiniehing t.he cm.poe!Uon ot his aeasage or the t.hte in ,,tJ.ch the writer 

ft.lea h:l'f"11tseaee in the masage center. It. intrequnntly designi..t ea the 

tiae a aange leaves lUSS&(;e center on its way to radio operator. 

10\a.t. are the relatiT• adYantatos and disadvantages in 'keei;in.{ t.he 

ftle da.te/t.iao in clear as at. pr6smt, =it.tine it. alto3ntl.er. or cid.phering it 1ntemallit 

(1) Tb.e da.t.e/t.i.'lle croup in al.ee.r allovs deduction• fJ"Olll tho 

correh.tlon ot da.te/timE- and t,n>e or tratfie. Thu•., a11• traffic 

at. a certain time mq mean plane• arriving, '3e:;>art1c, ei.c. water 

t.n.nlJol"t. trat.tic eiq refer to a. eitl.1.ation rep:>rl or coum7 llOVe-

...i.s, etc. Rclovin~ the date/t.iae ,group troll.\ the pre1a.~1.1>1e of 

WHP would not. eUainate abillt7 to Mk• thia deduct.:.on, for 

~ tt.al or. intercept. Um.• could f\lllction j u•t aa we·~. 

(2) ru. ckt.e/'111• 1roup lllowr~ eollect:l.ae ot part.• of •am';) aessage. 

:tntercept time functions just. aa well. 

(3) rile dat.e/t.1.rte ll'OUP can be ll&ed tor correl~tion wl t't\ 1 tternal 

auuge ftUllbers. 

Intercept. date/t.im.c !lft~ c1'7Ptographlc dat.e tw'lction Ju•t. ae well. 

(4) Can \he ts.le date/t.llll~ bo omitted altogether? 

in.. Ille da..t.e/ti111e all:Jws Uua recipient to evalutt.te the content• 

et a •98•ac;eJ SlDd proddes a check on the eQXin:~1nlc.ation1 interval. 

'114• aat be ft'f7 irr.pntant. Thtt .recipient 111 Wormed t.ha.t at a 

llGRSJ 
I ' REF ID:A71933 .. 

··- ... 

&i'Nl'l t..ov, the CIOntent.e of t.he •••eep arie Y.U.1d. 1t two 

ft.t.her eont.r&dlcto17 MllNC•• an ruelved, tt 11 !11Pcwtant. 

to kmw tbe Mr,.uence in which th117 •er• •r.lt.ton.. Old.s111on ot 

file ak/t.J.me 'llOuld al.10 :a;&'ko t.be •enicing Of •lhl:UJ 

·dlt.t1cul t.. ftao rue 4ate/tme ca.nr.ot be om1 tt. f'd. 

(.5) lboW.d tho tll• ate/tim.1 be ec::1ptiere4 .int.en•a!lJ'? 

!Ddptel'Ji;.ent ot dat../tille u blscc~ro e17pt.og1•a,1 .. ldcall1, for 

coh'ela.Uor1s a.t-e possible b.trcen 1nt.en:e;t rta.t.e and ll le da\e'" 

:r& .,uld &loo be d1tr1c\llt ~ 1dent!f1 •osna.ce l tor Hrric.1nc. 

SJ.nee int.ere~!- t. O.t.e/\iae 111ll function 1n J1Dat catc.t ae •al ldl.7 

.. ftl• dat.o/U., ed dnce lt 1a not. t•llible to .nc!pher- date/"'..lme grou.p 

J'1'0la "ou.rlL.r dowpolnt; slnco Ille dat.c/t.b:e provides a co~! e.ation 

-1leck •hlcl, C:.im:JOt. be ;rorided \ly ID1' ot.her 111C£119 ••••••• thoN aee::u. lltt.le 

NUOD \Q cll.acont1nut1 t.ho preaent pr&ct1cc ot clear 11.ltt date/tim· 11"'0\JP 

1n pnallblo. 

--- .. ~---,-·~---- ........ -- ~ - -_____________________ _, ;.