/ I
I I p. I I _., • CRYPTOGRAPHIC EQUIPMENT FOR EITHER . SINGLE-ORIGINATOR OR MULTI-OR_IGINATOR COMMUNICATION
l. a. Progress in the cryptologic field-during the.past few yea-,:s has .led to a basic change in cryptologic philosophy, a change Which has already oeen recognized by and is of im.,,. portant interest to the ASA.
b. The ti~ust which 'has heretofore been placed in the ordinary types of crypto-systems, the solution of which depends upon, or is directly or indirectly correlated with, the number of tests that have to be made to exhaust a multiplicity of , / hypotheses based upon keying possibilities, is daily decreasing. The beginning of this decreasing confidence i~ the degree of cryptographic security potentially offered by a vast number of permutations and combinations available of keying possibilities can be traced back to the advent of the application of ~abu~ lating machinery to the solution of cryptanalytic problems. _ Later, when specially designed cryptanalytic machines employ- ing electrical relays came to be constructed and applied, success fully to these problems, a real blow was struck at our former concepts of cryptographi·c security. And, now, the assurance that electronic cryptanalytic machinery can be a·pplied to l?Peed up the solution 9f complex cryptographic systems is tend ing· slowly to undermine what faith was left in the systems or crypto-mechanisms currently considered as being the best there are, those using rotors with complicated stepping controls .. , ·· . c. - To sum this up, it can .be said that, save for orie exception, cryptologic theory and practice during the past 'quar,ter of a c~ntury serves only to corroborat.E? the theoretical validity of ·the century-old dictum first enunciated by Edgar Allan Poe: "Yet it may be r·oundly asserted that ht1.lllan ingenuity cannot concoct a cipher which hµman ingenuity cannot solve.11 2. The foreg9ing summatJon is, as noted, theoretical and pessimistic in outlook. From a practical viewpoint, it can be stated that, so far as concerns the currently-employed P,igh e~helon cryptogl'.,'.aphic systems of the U.S. Army, there is every reason to believe that, despite the recent advances in cryptanalytic techniques and machinery, these systems are still quite sequre. .But for how many more years this may continue to be true is a matter of serious concern. ·The lead which our cryptographic· techniques presently have over our cryptanalytic techniques is not sufficiently great to leave no room.at ail 'for speculation or apprehension as to the situation in Which we might· ·find ourselves, say 15 or 20 years from now, when the new.ci'yptographic machines under development will _have
f~O~cl~~~Hied by NSN~S J ·r=-N~~e-~o ;NoT.~l~~t'iOYTeturnToJi~~-'. - . ~~.· ~-~. ·. - · · . f~ p i: · and Records f;= · ,c n cal library when no'longer 02eded Deputy Associate Director .vr o ,cyfi))ib'__ i,-"J::~ ·;: ·,; {' (" ~ /1 , 7.ri 7~ :uco·. . ".:...... ~' On 0~)}\ by,Q!!\lfljJ...,,Lr~ .,_;d.J \b!fwr~ u "·~· . /( .· ffe··tf"_opyNo. · .,9 - ·,·D"o·wo -c;r::;::r- ·,.,v OR \>/.l!'il'filt.~"lilf: ..~ l- ./. Declassified and approved for release by NSA on 07-16-2014 been completed. It is hardly necessary to note that the Research Laboratories Division is endeavoring to anticipate what the future may hold in store and is bending all its efforts to pro duce improved crypto-equipment that will be secure against a greatly advanced cryptanalytic art. Basically, these efforts are in the direction of increased sophistication and complexity in the present types of equipment, on the theory that this will always keep our cryptography in the lead of our cryptanalysis. But what if it should happen that because of unforeseen develop ments, in electronics and related fields, progress in crypt analytic techniques and machinery has actually been greater than that in cryptographic techniques and machinery? National security demands that we take all measures necessary to guard against such a contingency. 3. The sole exception alluded to in Par. le above, in con nection ~ith Poe's dictum, appears to be involved in the case of ·what may be called a "holocryptic" system, that is; one which is theoreti6ally absolutely unsolvable b~cause a message in it can be read only by actual physical p6ss~ssion of .the key. In a truly holocryptic system, if the key consists .of a perfectly random, unpredictable sequence of all the elements · (letters or characters) of the language, the sequence being as long as the enciphered text itself· and being a primary sequence (that is, one not derived from the interaction of a limited number of basic components), the cryptogram appears to be un solvable in the cryptanalytic sense. It appears to be impos sible to present or to develop any pract;tcal technique fol the solution of a truly holocryptic system as defined herein. It is to be noted that in the thr~e foregoing sentences the phrase "appears to be 11 is used. It is empl'oyed, advisedly, for it would be somewhat dangerous to insist upon a categorical state ment in the absence· of experimentation to demonstrate the positive validity of the statements made. -rt is indeed possible _to conceiv~· a theoretical general solution for certain of the so-called holocryptic systems, but no further remarks will be made in this paper on that phase of the subject, except to in dicate the necessity for further study.· 4. a. It is to be noted that there are three conditions which a cryptographic system must fulfill before it can be terme~ a truly holocryptic system: (1) the key must consist of all the characters found in the plain. text of the language involved; (2) the keying characters must form a perfectly, or at least an entirely unpredictable, random sequence, so that it
1Even were telepathy established as a. practical reality, the reading of a cryptogram by this means would_,not constitute a cryptanalytic solution.
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must be a'primary sequence, not a secondary one derived frpm the interacti9n of a limited nuniber of basic elements; and (3) the keying sequence must be used onc_e and orily once. In our best rotor-type cipher machines.the first of these conditions is fulrilled; the thir~ is fulfilled to a degree which, for all practical purposes,, is quite ,satisfactory; but as regards the second condition; it is obviou~ that although the keying characters in SIGABA, for example, form an unpredictable' sequence, for all practical purposes in the present state of the cryptanalytic art, it is not a primary sequence and there fore the SIGABA or any similar machine presently falls short of competing with the truly holocryptic system in security. As time goes on, it is poss1ble that the competition will not lessen in favor of SIGABA or its successors. '11his point is worth so~e elaboration. .. b. It may·be stated,.in view of what is now practic able and of what may become practicable in the near future, that, at least theoretically, whatsoever be the nature or cons'truction of a crypto-mechanism, if it embodies within it. all the crypto-elements of the system, messages prepa~ed by · it can and-will ultimately be solved. Only when the crypto mechanism is controlled by some external keying means does it present truly holocryptic features--and then only if that external keying means is properly designed and employed_. ,Even if an internally-controlled-crypto-mechanism is employed ·in a manner such that the internally-produced.keying sequence is employed only once, as in SIGHUAD for example, the system is still theoretically solvable because that keying sequence
is produced by th~ interaction, of a limited number of primary / keying elem~nts, that number being very small in comparison with the length of the secondary or resulta;nt keys. Therefore it cannot in the present state of the art be considered as . falling in the class of holocryptic systems and must be con sidered to be theoretically solvable. How soon i~ may becqme practically solvable is a questio!l that will be answerable only with the passage of a few more years. 9 5. From a practical viewpoint, it may be assumed that messages in a holocryptic system will never be solvable, no matter what the state of the cryptanalytic art may be. It would therefore be wise to extend the usage of such systems. Unfortlina tely, the last two condi ti.ons ·which must be fulfilled in a truly holocrypt·ic system impose practical limitations on the extensive employment of such systems in military crypto communication. The large volume of communication required . and the large number of commands which must intercommunicate make it. wholly impracticable_ to prepare and to distribute
·:;7. . the multitude of lengthy primary sequences that would be pequired. Moreover, the keying s~quences can only be used once. If used more than once; even only two times in most cases, such a system is quite insecure. 6. · It is usual to refer to a system using a pad of sheets of paper on which keying characters appear as a "one-time pad system", and systems using perforated tapes, such as the SIGTOT, as a "one-time· tape system". For the system using the SIGABA or similar equipment there is no analogous designation based upon the number of times a key is used, though supposedly such a system could be referred to as a "many-time system"--a designation technically too loose and inaccurate for the pur poses of this paper. The· real essence· of the matter is that, in the case of a one-time pad or one-time tape system, practical, almost...:absolutely-sure intercommunication is assured only when . there are but two copies of a pad or tape, one held by the originator of a message, the other by the addressee; and further more, an originator must not use as the keying sequence for any of his outgoing messages a sequence intended to decipher any of his incoming messages. So far as concerns the ability to originate messages that will' be absolutely secure, therefore, a true one-time.system must be limited in its distribution to one originator; for this reason such a system will hereinafter be referred to as a "one-originator system". A system such as the one employing SIGABA, for example, will be referred to as a "multi-originator system",' because many holders of ~he equip ment can originate secure messages and thus intercommunication among ~any holders can be pr'ovided. 7. a. The question arises: would it be possible, practical, and advantageous to have crypto-equipment which will, in the same basic machine, provide fqr truly holocryptic, one-originator systems as well as for.high-security, multi-originator systems? In other' words, what about.a single machine.which for the · greatest part would be .used for multi-originator communication, but whfch could, when special circumstances dictated, serve also for single-originator communication? · b. The possibility that such a machine can be devised has already been demonstrated in at least two cases. The first is to be noted in.the case of the obsolete Converter M~l34A, wherein the angular displacements of _the rO-tors of a 5-rotor crypto-maze were controlled by perforated tapes. Multi- . originator communication was provided for by issuing the tapes in sets of 48 and using them according to the variations in dicated in a key list. To employ such a machine by-the use of individual tapes according to the single-originator system is obviously possible, though it was actually not done when
4 Conver~er M-134A was in current usage.·. The s_econd example ·is to be noted in the case of SIGSALY, .wherein holocryptic, single-originator communication was proyided for by the use of SIGRUVE records and high-security, multi-originator com municatfon was provided for by the so-called Busch machine. The latter was hardly ever used, however, for various reasons, mostly because of mechanical or electrical difficulties, not for secur.i ty reasons.
c. There seems to be l~ttle. question of the practic ability of the idea of a single machine capable of serving both functions. "If the basic equipment is designed to incor porate the idea~ and is in·itself practicable, there should be no problem about providing for the dual function by means of suitaple a~apters or cooperating components. For example, in the case of SIGABA, it. is perhaps possible to provide a "basket" or crypto-component in which the control and index -rotors are replaced by a tape transmitter through whi~h could .be passed a 1-time,tape. With the normal component (present SIGIVI), the availability of SIGABA for multi-originator com munication would remain intact; yet, when occasion demanded the assurance of absolute·security, this could also be furnished by the special component.replacing the SIGIVI. d. As to the advantages and disadvantages of the pro posal, there is no doubt that.it would complicate matters to a certain extent, but the advantage of having a single machine capable of performing the.dual function and of affording not onl·y highly secure multi-originator communications but also nearly-absolutely-secure single-originator communication is obvious. Even now there would be a practical usa~e for such a machine. Recent cases wherein question has been raised with 1 regard to the security of specific .messages demonstlrate the point. "Eyes Only" messages also demand special treatment. But of' greater significance is the importance of having such a machine with -vrhich to face the future. For, should ·it turn out that 15 or 20 years from no~r the actual progress in crypt analytic techniques and machinery approximates or surpasses the · expected progress, we should not be caught unprepared. Our security equipment could still meet the·needs of security to a better degree than would be the case if we proceed-on the assumption that our cryptography can always be advanced, by increasing sophistication and complexity of construction, .to be sufficiently in the leadof our cryptanalysis to permit our confidence in the security of our equipment to remain undis turbed. In short, the proposal here made is in the nature of an 'insurance policy against unforeseen contingencies--we ought not to allow ourselves .to be caught in an unfavo1'able. communi cation security position becaus·e of wholly unexpected develop ments or much more rapid improvement in our signal intelligence position. · ·
5 ".. ~lT:A41272i6....
8. It has been suggested that as an alternative to the dev~lopment of adapter-type components in equipment designed to be capable of performi_ng the dual function outlined herein, it would be possible to issue special key-lists and use a specific keying arrangement once and only once; this being nearly equivalent to th~ truly holocryptic single-originator system under discussion. There is no doubt that such a scheme would give added security, ·but it does not me.et gui te· squarely the issue presented her~in. The point has been touched upon in Par .. 4b and the argument therein presented is equally applicable kere: · · , 9. If the principle or proposal advanced herein has merit, it could be adopted as a general policy to incorporate it wherever possible and practicable. 10. It is recommended that: a. The propqsal suggested herein, viz., that future development of security equipment be so directed as to .fn corporate features or components which will alternatively· .permit of' s.ingle-or•iginato11 and of multi-originato11 comrmini cations by the same basic machine-, be studied to ascertain its merits. b. If the proposal is found to possess advantages important enough to outweigh its disadvantages, :i, t be. considered for adoption as a general policy. . . c. Cons.ideration be given to the prop9sa;l in connec tion with the current ·revision. . of SIGIRA. d. Some research and study be given to .the question of holocryptic systems to ascertain what might be accomplished by the use of' new machinery now only dimly conceived but perhaps possible of being constructed.· · e .· . Further research and study be devoted to a careful examination of the nature of our.present mechanisms for the generation of our 1-time keys and of the nature of the cipher alphabets employed in connection therewith for the encipherment of classified communications. · . (UJ' ' ~~ .. WI~RIEDMA~ Chief, Communications Research 2 May 1947
6 . . . ' ...... /f/-J-?"'{;y/..:{ ~ INTER . TO. FROM DATE 'SUBJECT Cryptographic Equipment for Either Single .2 May ~ Originator or Multi-Originator· Communication· AS-20 .AS-14 7 1 The ttached .paper is submitted at this time in connection with he cur ent re lsion of SIGIRA. 2 The ubstance of the paper .is to recommend that serious c9nsi teratio1· be·given to an extension of the potential.usage of .1-tim s·yste s by _providing. adapters for use in connection with J ~~) c rrent rypto- echanisms now generally operating only as ';rnult·'ple-co ll11Unication" equipment or (b) similar mechanisms now in th resea ·ch and. evelopment phase. - q;x~a.G-~~ · 1 Inc WILLI.AM F. FRIEDMA'N . . . Pap r on Cryptogra hie Ohief, Communications Research Equ·p~ f6r Either Ext 215 Single-Ori inator r Mul i- Orii;;inator omm. 2. AS-14 AS-23 21 Jul 4 Major Moak 462 . ) . 1. The inclosed paper on Cryptographic Equipment for Either Single-Originato·r or Mul ti-o'riginat.or Com munication has been studied l?Y Operatio:r;i:s Di vision, · Research Laboratories Division, and Security Division. 2 With to the recol,llillendations contained in paragraph 10 of the inclos conunents are made: a. n~zed that holocryptic systems provide the only the ore .ica.lly systems. At·the present time~ however, the employment. of h'ol cryptic s is accompanied by a number of serious operational as well a produc istril;mtion problems. · Further; in the case of low echelo crypto echanis • a requirement for the provision of infinite· security · has no been e tabHshe .,,In the case of high echelon cryptomechanisms, it is agreed that, w enever p acticable, holocryptic principle's should be embodied in· multi- rigi~at b. •. , ent work on SIGIRA, account is being, taken of a basic mili ta ~ requi a. one~time mecpanism to ~ulf ill the need for holocryptic system 1.~here equired. ~In. :this conn~ctiori, the questi_on arises a$ to whe"t;her, at:.··the· -pres~t- §te.i..J:J.. of devel<;>pment, it might be better to achieve speed a:i;id . : Deel sifiea by SA/r:5'5 Oepu Associate Director fo Policy and ~D~~=}~:;;;1-9; by l?ffl I PAGE NO, ___ '.!6 Nov 45 36900 LIFT HERE USE OTHER .S.IDE •-'T~O----F-R.O_M___ D_A_TE ___ S_U_BJ_E_CT---"-'\-';,.:-=---- .. -_,·'?~;·~:~·~l-z72Z------~ . ~ /", ~i:fbidlEquipment for Either Single- AS-23 Orj gi natar or Multi -Ori gi net or Communj ca ti op ligh't'.-· e~ght, i evi:ce,. issu:i.ng. it to all hq;l,dE}rs _for: emergency ·u~e, rath·er ·than to burden IJi chine13 :·qe~ign~gi pr~-qiar;ily-·for niul':t1,~o;r:::i,gi~ator ll;Se.,. : , Se~tle .en~.~~ '~i~ '.~u~~.. iqn;)P}iJ~~ ... Q~Vi9~f!!Y~·~w~i t a' ·~9r~. a~~nc_~ ..c. 1 -.+ ptov~m~n s iJ;;l the methods of '.g;ene:rati~g. perfl'ctly random, ~pr~ ,J :":~·:·~'.T<'·:: >-~:_,~a.·-. • . . . -- .~/2~C ,._ .. -. . ' 1 Incl - . . PAUL E~· NEFF', n/c Lt;· co1oiie1· :·:·gnil ·:corps· -Acting.. Depu Qhi.ef Army Seoufi ty.. Agency . _ .... Ext 498 • -.! / • 2o AS·l4 . AS-23 21. Jul 47 : . Ma-jor Moak/ 462 . . L .· 'l'he ·i~olosed paper. on Cryptographic Equipment for Eithar· Single-Originator or Mul'ti~Originator Com-_ munfoation has ~been studied by Operations ~i vision; Ras~arch,- Labor~tories Division._ and .'.secur.ity. Division. : ·. . • ..• . ' l t l . . ' , •• 2o. With reference ·.to t,ne -reoommenda.tlons. coittained iri paragraph 10 of: the inolosure~ :the· 'following -comments are made,: : · . ' . .. . ' . :· - . ,· a. ·rt is recognized: that holocryptio .syst~ms provide the.only theoretically unsolvable systems. At the·pr~sent.time~ .hoviaver._ the employment· of holoceyptio pr,inoip~es-_ is accomp-an~ed ·by ~- nurilb~r of sariotis~ operational as· well as produc:*;~on arid. disi;ribution ·problems.. F~rth;er, in the. oase of' low . echelon prypto~echanis~ a requ_iremen.t for t}le :'pr9vi.sion _of" infinite security ' . has ~ot been ~stablished.,:._ I~ the cas.e. of high e.oh~ion, cryptom:eohanisms, it '-is ~greed that, wh~never"practica.ble. :·holoc.rypt~c pr_inoiplt:)s sh~µ,ld be emoodied in multi-originator mechanisms.' . .. ' . b. In. the presel].t work on"~J:GI.&.· .aocoUn.t is-b~ing taken of' a basic 'mili ta.ry requirem~nt for ·a one'-tiine-,mechanj.sm to fulfil.). .·the neeq for holbcryptic sy~tems where required. ' In this ·connection;. th'e questi.on arises as .to ~hether • . at tho present stage of: develo~.en:.~, 11,A:;t~dllig"tr'lt)·Q.e bett~r to. achi~ve speed and \'f~f;'~ A ~'!cn:.~)~.l.A VtZ'~!ll~A 1+z·io";{tY:::S.LE:~e: . ~a:·--. -~~ET . · . ~ · 1 ~);,~~il":r · SECR~E" .-'r~\"~4121221: ' '. ' I • Cryptographic Equipment for Either Single- AS ... 14 AS.-23 21' Jul 47 Originator or :Multi-Originator Communication • . '-1;,. 1' light weight in such a deviQe 11 issuing it t.o all- holders· for emergency _use,; rather ~ha.n to burd.en ~chines, des_ig;ied p~bia.rily for multi-origin~tor use. . ·settlement of this -question muat obviously :await a more· advanoed stage in the . development or cryptographic' deVices now· ~der oonsidt?ra.tion. · , · o c. ImproveI!lents in the methods of generating.perfectly random11 unp~edictaple key for use in connection with holooryptic systems are-~0'!1 under study by Security Di vision~ · I . I · 3. In view of the apove 11 research· in the d~velopment of all .~ryptcigraphio devices should incl~d!' oonside;rat~on of h~~ocryptio principles in _the' provision of dual Single-originator - multi-ori·ginator equipment. In .this connection it ' is de.sired that the Chief. C'91.nmuilications. Research Section: ·continue to pursue matter'and insure,. the th,i'8 1 through·coordination·with var'io~s· operating.divi siQns •. that oontinuing cons~dera~ion ia gfwn the .. recommendations· contained in the inolosed paper. 1- Incl PAULE. NEFF .n/Q . Lt. Colonel •. Sig~l Corps Acting' 'Deputy Chief A?'tnY' Security Agency Bxt 498 . ' . \fH!AL!t 2E.cn1£U.. ;., "11:,:~MCA . \-{E';/!:i;'.)" ';i'!::J.LF~e ., . \ . ~ . . ··. i . '~~:·:-·-i;;, •. t, , REE.. ID:A4127221· @~'!!;eJtt::! CONFIDEN'II.AL ---rtJ.';S·_;_·1:UGT.@ Td DATE '/...I ~ 'f y I?ROM --'- Commanding Officer ---Assistant Co1mnandant-....,.-----~---;-..;...~ · · ---Dir of C?I"ili~ Research-----;;;"~·=--.·.------Control 0 ------Administr-a~t~i-v-e-cO,,------'------Adjutant Intell i gen------,=------c e 0 . Frovos t Mars ha-=1------.:..-- 2nd Sig Se,rv Bn------, Chief, Pers & TrnG Div ==== Chief, Pers Er ------,--- Chief, Trng Bi· ------Chief, Oper Serv Div ---- Chief, Communications---=------Br ·Chief, Laboratory Br ---- . Chief) Machine l3r ------Property & Supply--=------....,...---- 0 ,.., / Purchasin1; & Contracting. 9-._;,,.--- ..... Fiscal & Certifying 0 .. ' OIC, Mail Section ~ ----...,..-:------'• .~~- ,. :··. ! ... .-:· . 't·· ...... •.. ·".. ., .. ,f ,.... , . C'hief', Securi t~r Div· ,, ;";; ';" 1· --:--- ChiE;f, )P!;·otective SE'.c· Br . /Chfof, yryptographic Br ---.- ~/ >. :::::J2'.'.S' iCl'r:i;e:f,:; f)e.ye lop:mep.;t' ..!~r. . , . ' .:' ,, ..· .t .. _ . i . ' ..,..,--.'-\ ---- · i \ Chief, Intelligence Div' . Chiflf, 12.nl!,uage. Br · ------__....,,..,,...... ,.r;; ~->Ti-;;,.: --.n~, .. I J.. , .• T-' .... C)iief, hli C17puamuyt1c ... r --- Chi e T~ Gen Cryptanalytic Br------Chief, T/A o.nd Cantrel Br1 --- Chief, I & L Br ---~------ •As discussed ----w · As requested------,- Cor:iments and_r_e_t_u-rn ----Information and file--,..-"------Info rm a ti on and forwarding------Information and return ~------~,COmr.lenda ti oi1______VSee note on reverse -----Signature if approved--=------~- ----Your actipn ·----~----,..- SIS-SC~Fo1m rto. ~6 (Rev) .23 ·August 1 944 REF. ID., . A4127221 ..' ..().I . lf\ . . ' , ..... - . ~ ·- . t ...... , ~ .. .' , ...... : .. .. ~ ' RE·F ID: A412 7221 Date et_( ~·ez&/f{(/" From~ L;;rlcs ;;Jr . Col Corderman______._ Colo Collins--..------· Col ~-· ' . .... . -~t ~~ ·" ··_: :_· * .. ·.:· •. M,•' ' •• • I' ,• - •' •' • • . ., • ~ ,' . -::• • •.. ~ • • ., ·.:.- :. · current Developmeii:"ts·~:j_n'. -:i:rit·e~cept·· :Equipment . . . . Lt·. :..:c~·oi~ ;Rose~- ~~iitiq~ea>a -~~~lee ·~rhich :is bei~g·, constr:.ic-. · · · .. ·· .ted-':.for· fu.ar.king :"t;;he Baudot 'start. ,p.tilse p·osi tion on. u:hdulator · '. . _tapes. .·) .· .-,. , .... : ... .. ' . ' : 1 .. -...... - . ' ·:''I:, _,-. ·- . ! . .• I• ·.. ' ·' ., ~., ~o;cl~~ifi~ci b.f NsNds :, ;. ;. .. . :. .·... ,· -~. • j ... ·. ; ~ ... : •· .~· .. " . .... · 0;p~tY ~ocia~e Oirectoi for P.o_licy: ~n_d·Rec~r~~ .· .,. : ·.. 1 __ • .~ ... ' . . ·-c· .·. ·_,_ , __ ,,, ...... ·.on··~P.U.J..~~5.:b~ -e~r ··~ ! ' .. ._:.. _...... '· . . ' . .- ....._ .. , ' ·, ' .. ·: ...... ' '· _ ·: ....: .. · -~ .. · . ... ?. · .••. . .. ·" . . .· i. , . . ~ -; . - .: . . . · ... .: • •• l .. • ': . I . ···-:.: ' r ._ - .... \.. .···· , ..... <>i. ·li~rf?~~. tf .;' · ., ~ -.· ~- --:· · _.-._: :~ - · W·WJfw··:--:- IiJJ.tlLIJij.~tC1L' .-- >·:., ·:,----.. · · -:-- -- - .... ·- . ,. : . ·.' •. •. . . . ·.··. .: . .·.. .· ·. . . ~ . . . ' . ·~:...... ~ .·. - . EXTRAOT:-FROM FIFTH.-DETXNG OF·-·Arua;;.NAVY ·oRYPTANALYTIC RESEARCH:'-:- ,... ·.:._ . • • - ::- AND ·D~~C~)PBmNT QODJ:TTEE . 15· NQ~-i;R +944: . .-::·- ·; _>: •' - • .... • • ... • ~- .. • ··:· ~ ' •· ··.... • "... • •. - •• ": ._~ ' •: • .. ~· •• • ' ' • • ,.- ..l. --~- •• • . 01 ~.' !'", .. ' , • , ,' ' ;· ' ' • ~ • " f' I ', ' - t ~.;. i• ·· • • , . , . --.-- ...... -:=·----_.;:*':·o--~- .. ~:.-:t>-:<>.-:~·-o"o -- · '·; ,.~·-·-·_ ·-·:·:," '"'· .. ,·,_-~ .:- -_-; ._: . _:._. :- - _;- >:_ ,.:.. ; .: .. ·: ::::::-. ;:_ ...,: .. -- . "". ::";' _--. ::::_-.,. :.< -.:: ~-- --· : __. . ---" '-: ,,_.· Chirr'9nt- -Developments in Int'ercept EgUipnient · . : _ · : · -.. · - ·. ' .,.. " - . . .• . . - "..:• . . ~ . ·• ·.-·'. '.,.. .s. :::· . . .. -:- _Ltq,--Oolo-- ~osen ·mant~_one_d _ra;·~~vice --ifhich.1s-b~~g construc tad ·toXo· fu.l.rking the Baudot· :start. pulse position on UD.dulator - ·tapeao ~-;.-This deviee 9 ·if'. s~ccess.t'11:~- wiil gr_eatly _facilitate ; th~.·read1ng :_of,tape reco~d.s"o_t ·s·un1t cod~ tr.ansmissio~s-o - A-t done'.'.·by,_,~-~do'; · ..• , GOCS.:this marking'-'is·- . -... · ::--'. · :,_- :.. - - .. :. :- . ... . ·...... -'. . ~ -·· . ' . . ,_ - -·-, -~~ -- Bl.lorr.is stat~c{ t~-t ·the ti~~, -delay ·;~~~rder fs. under~- - . .-: . - going test .~t;-Vi-nt'_Hi_ll.'!. ·:_-;~:-_:a ;~uzt~e~t _seo~_:i.:ty monitoring- . · mission' in .. vhi_ch'mUltitone --~eletype .transmis's-ion·)ras trans- ... :mitted on one side ·ban.d,-_~d.)1p~e~h.. on the otherJ) the delay dsv,ice -made pos~Jble ,an arra.ngemcant by ·which ·all talephone - -communication. vas: recorded.-witho.ut· the ·long intervals ·'.which _'". -. _. li.C~ually. occur· between· txian~~ssi'ons and wfthout ~ l_OSS of any _ pa.rt. of: th' comm'Unica.tion·~ ·-· 'It was. suggested~· th.at this··method . i!ii of. signiticei.xioe 1n·--co_nne~.tion,with .. telephone monitoring -of _ any sor.to 001"~ Prie-Clman point: out _t~t· this- ·¥as·_~ means of_ . · -··· e.ccomplishing _wb.$t papt .. }ihoads-·had ·sugges-ted,_1.n: 1935&"----~~t ~ - -,, . -. message be. c9pie~ by aut~matic .. mea.ns only :w:here .such ¥tri -identt- . -- - f'yillg vord a:a, ETAr;r.-appe!!Lz-s· 1.D. -th~ --transmission.»- thus· saving:.,-· -- _ ·- . . monitoring._ time o .- . Capt o Wenger -:reported t~ t the_ P/L equipment ·_ <. vill •-be, set. up -~empQrarily·.a:t 'Ska.gs I~· ~t.il.'sc>ln~thing furthet' - .·.·, .. _--_ d0velops ·on" 1:1o~a~pl~~~ -.8.l?.~~-~p._.:tr.'?>~~~ssiop.o .- .~.o. Morris_ saici - _. _ .. none of -'the. latter».~.1~-eo '"Japa.ne-~«3 :orig~ 9 :",bad~be~n--observed - --.for a.:yea~~:~ - .-.:.·~ .: . - -·--:->·.~·< .,'·,. -\-.·· «::'.._._-.· __ · .. -.- _ ·. -~ . . ., - .. ·· .. , . ,.._. . )• . '.•.:.:.... ··":: ...,!.' :.1·: ., ;· '', '"· . . ': --~:;· ;; . : - _.. . ! • ~ • . . ·.~.· • '.:· .; . .. , ... . .: . .- t .• • . c ·.·• • - , . ('< ~ ..... - '· . . . -;; -~. · .. :,. . ... ,'' ,•' .-:: ' - . ~ --~\~ . :_...... ' .· .~ -:~-. .- •. ·.:. . • . •. . . ' - ~:.• .·. , :'! :. ... . .. ::· ·. 1: ~ -. ,• ~ -t - ·, .. ~ : "::'. • ~ . . . :• ...... J..°.:. . : . ~. ' .. . ; ·... ' ~- _ ·: '·····.·· ·... •. -. ' '• ~·· ;:. '·. . ' ..~ ~- .-~~ ~: ·:~~ ' - ·:t _!1· ••...... ~ - - . 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