REF ID : A2 4.3°6-2 0 6 

s E c RE ._('ECURITV INF0RM.\1'16rt 

AP&J!Y - P!!m l!!M!Nft2!! 

&EJYil Rt AD OOC COMMITTEE 

tp the 

All@? mRQES SFXURITY AGENCY COONCIL 

al 

~ OF U UM!~ ~aruN;J:PJ:.'flQlf ~qlgj~TY CO~Ea 1922 

l. To etud.J' the 1r..1Plicat.ions at paragraph 9d ot "Report. ot the UK'/US 

COMSFX: C<mterencett (AFSAC 63/63) which rec<D"OOnded t'elease or the British 

device ''.MercurT' to NATO. 

2. To st~ the question ot the releaso ot the CSP 2900 to tha British 

£or purely Canbined use, as an interim solution to the replacemnt or tho 

4• It ie concluded that: 

· .. ~ A• P~ 9d or "Report; or tho UK/US CC.MS.EC Conterence" (AFSAC 

6'3/6'J) should be approved. Tbe:re sholild, however. be added to the 

report a general. note to this etf'ectr 

"In all cases where cr,ppto-equipncnts, are to be made ava:S l a1iJ o 

to NA'.ro, the revelation or cr.vptoprinciples involved ehould be 

:restricted to general aunrnar1e8 and descriptions~ and should not 

include specU'ic wiring details, drawings, etc., until atter the 

equipnerxt is in production.'* 

lz• !he develo:pnent by the UK ot a cipher machine incorporatillg 

principles so similar to those or the CSP 2900 u are those ot 

"M~ makes it obvious that the principles or CSP 2900 can no 

J.onger be regarded as the exclusive propert.7 ot· the USt but there 

l 

Declassified and approved for release by NSA on 09-26-2013 pursuantto E .0. 1352a 

SECRET ·.=.·;;.· ................. ·- ..•....••..... - .. . . . 

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· REF ID :A2436206 

6 .:. c RE T. St.:lltifll' fffF6RM~Jl9N U.CiE = SL\mlll Bf211Wf!OH 

1a still val.id teason to:r: continuing to keep rran the UK detailed 

knowledge o! the CSP 2900. The1"0 ie not, hawever, mv- val.id reason 

tor cont~ to keep trm. the UK detailed knowledge 0£ the F.CM. 

£• Th.ere are uses, 1n Caribinod camnunications, to which the a'U"ailable· 

quantity or Emfa ntlaht well. be put,, am. these uses would improve the 

11ecul"i.t7 or Canbined camro.micat1ons. 

f. It is reccmnended that: 

a- The conclusions be approved .. 

ll• The meioorandum attached as ene.losure be forwarded to the Joint 

Chiets ot start. 

s.•· The ttaeport. ot the UK/US OOUSEC Conterencett be amended to include 

the pal'a#apb contained in ~aph 41 ot the CQ1.Clusions. 

2 

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REF ID:A2436206 

s C: c R c--rSEGYRRY INreRM.\ltGN 

@RF.it - gmqxr PfQBfoti!I 

I ?f g .. 0 s g B ! I ttArt,. 

121AP'l 

~! mt . .B,J01J.il'. mYl&l.QF .... ~ 

SUBJF£Ti Releaso ot the Principles ot the CSP 2900 to the 

U .K., C&nada, Australia, and rtew. Zeal.am 

i ... '?he c1Jiier machine CSP 2900 an:l ita predecessor, tho ECK, have 

been Mainad !'or exclU&iW US USO Ubier tho terms ot paraerap.11 308130 

~ "Joint Action of the Atmed Fol"Ces._tt 

2. The .bmed ForceB Security Agency Council, having stud1ed the requirements ror improving the securitJ ot Canbined caam:Scations With tho 

United lingdm,. Canada, Australia, and New Zea.lard• now :rec<qnends that 

t.be princiPles of" the ECK be authorized tor .re3Mu$e to the abo-re-mentioned 

countries. and that issue to them o.t the ECM, within the limits ot availabilitT., also be .cthoritsed. These recotlil'lll1'ldatione &"8 ba$ed. on the 

f()llowing reasc>nina• 

a- nie UK hes developed.. tor C~th uae i111d tor otter to the 

llA'ro mt1ons,. a tel'St7PO cipher ~ht.no Jmown as "l.fercur.v" which has 

a cr.1}ltopr.1nciplft Wt.7 sim1lar to that or the. CSP 2900 and is ad.Judged 

bJr" the US expert$ to be tnen more .,acure. The shdldt.7 in pr.1.nciple, 

even though the details ditter and the CSP 2900 1e not. & telet:yp& machine, 

makes it apparent that tho basic pr.lne~e ot the CSP 2900 can no longer 

be considered ax:clus1~ us.. '1bore 1a no evidence,. bowe.ve:r, to indicate 

that the details or the CSP 2900 are known to ~ otber than us 

panormel • 

.Q. The .rm. al.though ccmtain1ng the 8811111.l basic c17Pf;oprl.nc!ple .-a 

the CSP 2900. ditters 1n detall to the ez.tent that loss ot the ECK 

would not permit uucco5etul. cr.JPtana:Qtic attack on the CSP 2900. 

£• The CCM.,, 1n current W» tor Cmbincd cama.unications, is out.moded, 

tad.at.a in 1nrmttic1ent q.iant1t7 to meet all da.unds, am, pe.rticul&r)¥ 

.trait the standpoint or b1gb camr.md cairJUni.cationa and thoso dealing 

with intelligence, 1a COD$1dered 1n.adeqμate. 

l 

Declassified and approved for release by NSA on 11-21-2013 pursuant to E .0. 1352a 

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REF ID:A2436206 

a. The US Al'med. Forces are now operating urxler an agreed "fl.an to'l:' 

the Devel.opnent and Dee ot C::vJ>tographic ~pnent and P.rin.ciplee.11 

tbe 1~range portion or the plan provides tor the devalopnent ot 

equipttenta wtde.~ will be retained tor exclusive US use m both the 

literal aDi tho telet.r,.xt ca:minicat.1ons- .-ecuritq .tiel.ds • 

... In the 111Bantito t."'ie us. altlloU&h releasing the detaUs or tho m1. 

1fl0Uld continue to retain inrlolate the details ot the CSP 2900a lle.tenti.on 

ot these details tor exelusiw US use aatist1ed. the ~nt ot pa.ragrap.'1 30a.JJe of ft'Joint Action ot the Armed Forcos."' 

3. It ie ieccanet¥led that tho Joint Cbie.ts o! Stat.t ~rove: 

J:• Diacloaure ot the detail.tt of the FlTM to appropriate British 

authorities (CJPhor Palley Board) b.1' the Directoi-,, Armed Forces Security 

Agency. 

la• Initi&t.ion or action lV' t.he Direotor, Armed P'oroes Security Agency1 

v1th appropriate British authorities ( c,ph.er Polley Board) .tor utllimtion 

in Canbined ct:wrramications or such mis as can be :made avail.able. 

2 

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REF ID:A2436206 

llQLOSURE "art 

l. With regard to part 1 or the p;roh1.emi 

,a. "Mercur.y", a Mtish~ted device, ·contains Cr.YJltoprinciplee 

so a1:m:Uar to those ot the CSP 2900 that to otter the to:mer to NA.10 

$;»)Ullts to g1ving aw8iY' those pdnciplea which the US has :retained tor 

its own use in the past • 

.b· Loss to an enem;y or the "1-~ would in no va;y endanger the 

MCU1'11ijr ot US camnunica.tions enciphered in the CSP 2900, since. 

although similar in pr.inc~, V.orcurr and the CSP 2900' <litter in detail. 

G..• Ccmiplete revelation to other NATO natl~ o£ the minute details ot . &lV cm>\ opr1.Miple pri.o~ to itG embodiment. in a 'IDBllUfactured 'V'ersion 

1a a ~tue to be avoided, aince auch detail \JOUl.d pel'mit a nation 

to produce itfJ own embodiments even though the .t1.nal US eqJlipment m:lgbt 

be ottieial ~ rejected for HA.'m use. 

2. With X'Oprd to part 2 of the problem: 

..., Tho CCM eunen~ in use .tor Canb:tned u .n as NA'ro trattic is 

QUtmoded and inade~te, pa.rt..icUlarq ror b.1.ghest-leval and 1ntel.11gcnce 

trattic. 

\ ll• The appeannca ot tho principles ot the CSP 2900 1n "l'..ercul'J"' Mkes 

it obviol.1$ that the e17,Ptographers or the Ult a,"N. tho~ fam11 iar 

with the broad pr.lnc1ples ot tbe CSP 2900. 'l'h1a doos not mean. hawevor,. 

that the UK 1a tlun.1.liat' with the detaile ot a,wl1cation ot the principles 

Within the CSP 2')00 • 

.G.• The CSP 2900 incltde::l tJle t;~ basic principles a& doe&. t.he- tt:M, 

it& predecessor• blt a.gain <litters su.t.Cicien~ in detail to mean tha't 

tvVelation of the pl'inc4>J.es o.t the Pllt wuld not. provide exact knowledge 

ot the CSP 2900. C~ic attack 11fith b1gh #peed analogues reqμj.Ns 

knowledge ot spec1tic detail.al t.1lere.tore, even Bhoul.d knowledge ot th& 

det.a.U.a ot tho m.l becane known to an emmu e~t, be could not 

1 

Declassified and approved for release by NSA on 11-21-2013 pursuant to E.O. 1352e 

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REF ID:A2436206 

use that knawledee to direct intelligent:cy- a high. 8peed analogue 

attaCk on the CSP ~ 

.II,. Release ot the ml to the UK would pel'ait. use ot a veey stl"Ol'Jg 

machine tor same Canbined cammunications am. would •till permit canpliance with paragraph 30SJJe or Joint Act.ion ·of" the ~ Forces., 

which requires retention tor ex.elusive US use or our most secure 

cr.JPtographic. 878tem• SUch releue would not jeopardize the eecuriv 

ot US camm.mications • 

.f.• !here are not autticient; ~antJ.ties ot •it.her CSP 2900 O'I! F.CM 

in a:t.etence to pe:rmit. the otter ot attY"" lar&e quant1t.T to tho UK. 

i'boT are surt1c1ent, however, to meet scae or the aore urgent h1&b. 

~and special reqμirE:=ent:s. The me, if' such an otter were to be 

made, should bave a voice in det.erminine the uaes to which the qμantit7 

vbich could be ottered might best be put. 

Enclosure ftJJ" 

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