L 

ursuant to E. 0 . . 1352 
n 

I. 

I 

\, ' . 

' .. 

... ,. I 

I • .• i . 

r 

" " 

.. 

.I . ...;.'.\ '' . 

.... ,"!:'• ·' " . !' I 

I' 

.. 

I 

' ,. ' 

~: . . ' 

: ~ 

,. 

' .. ·. 

''•:•I• 

.. ,, 

' .. ·~ i .... 

I 

I • 

. ~ ' .. 

. ' ' 

l' . .ti ' 

' 

:., 

' ' . ... . .· -;~ . ,:.'~.-~~' 

REF ID:A52149B 

!hie 1s to make a record ot the date or conception of the tollow1iw·. modU'1oaUo0. in the Navy Cipher Mo.chino being etud1od in th1e ortt·c;e· et; the 

. . . . 

1. Let .there be added a Bnt1dot tape transmitter e~io:rtpg· th& ua~l :· ·:: · :: .·). 

•. 

~ ! ' .. 

1 

. :· 

i. 

; ·• .':,.< ' ,; • '. . '. . · . .' • ' •. 

t,ype -~t perlo~at.ed tape •. Let th1a tape be used tor .a ronni~.k~,. ~xcept. th~t:. · J .· . ·.·:: :.~ .. ··· .. ~- ·~:::. ·~ ·~ ·. ._,. ., . :-\~~·.~;~> ........ .:· .·" :, ............. ·,. ·.: ,,. .. Qnlt tbe. '.tollo'Wihg: six permu.tatione are employed on its - ->.;;. ~ . ...;, :+ . .;. ~ .·.~, ..;,~ . · · ·) ~ . ·:· . ... . ' ' : , . 

. . ,'.:. \· ·. \ ... 

- + ..... ~, - -J + -.. -, ~ - - t \:-• and - - - - +• The tapa mqJ.te..-.ot·a' ti.n1.~e ··or· .. ·. 

iat1n1 ie len~~. .>· . ~ :.; 

.• 

. ~. . . ' 

., 

-~ 

. . . \ . . . . ', ·a. ·Le,t the ~a7-tape tr&nsmitter be woed to control tbe ·action or fin 

.P~tl . . . ·~ach . ()r 1llbich 1n turn controls the movement ot on$· of"-:.th9 . rtV.:ciph~r . 

·•h$ele. · ·'l'hua,· by use of the key tape, an absolutely irregulo.r ~e1.:·ot·.d1a. 

" ~ ·<·:"-' · ·· .-r· ·: · ". ::- (.... · · . · · .~:!~':·~: -:~:3~'.:_;: ·~·;.'·.~·_·.· ... · . .'.'._.: .. _·: ... ~ . ·. plaoementa of :the· set or cipher wheels would be bro118'1t 1nto:.::P~'t:,·::1~stead· of 

•-:~l,.~alited n~l)~r or displacements, regular in character,. sa .. ia,:;_t~e· ~~··~ :_.1n .. the 

·.·· . 

· ·.· ~. - As~ the tive cipher wheele to be in a given i~t~·'poett1·~~ 

~. ' ... 

.. , . 

lo~ ~· '.:.' ""· ' ~:~> .. j·o,' I '\:• • \ • • ' • • 

Lett the arrangements be such that with each depreesion of a key ot the ko,yboBI'd : . 

· th.• -~.~·-. atep]j~n,~rd magnet or ~e ke1-t.1tpe trrmsmttte~ 1·fi ;~t.~~~(:~o":~w , . ·-_ · ... , ,. ' ' ; ' ",! • '• ~ ·. ,' .:•;• .'' ~. ~· . • • • ' I 

t~e '.ke"'· •e.pe. tonard one step. sa.ppoee this nen aett1ng or:::~·be.-:·~ap~:·:l)r,..agl 

'1p ·i,'p·~z:o~t1~.C 111 position number 25 thi~ woU.ld cause c1ph~:r.~11G.ei .nW!tber 2 ' ' ., '•, • ' ' > I 

to at_e.p.,fonarcl"o~ place. Thlls, pertoratione l, 2, .:s1 4, 5.::cont~oi,,·~eap•cti._ve~; 

tiie·:'\11~J.~6emen.te of cipher •heels l. 2, 3, 4, 5. Bo perf'o·r~tl~n (blank) in.. t~ 

tfpe (perm11tat·i~n - - - - -} ce11se8 no wheel to be disPlAoed> But thiD. ~apeoti?.e ·. . . ·...... .·. ' ' ' . 

J".ele.tlonahip i·s not essential; tor by interposing a switcbboard·~r .t~e t,ype cov~ . " . . .. · .... : .. . , ~-·::._.·.::~;.=-.~::<·.... , . . .. " ' 

.'.~~r,_1n.iv .. O•~~ .. ·patent nwnber 11522,775 ot January 13, .1?~1:.\~~~~ti:Wmit:ter PS:A•:·· ·.:.- .i. 

:.,·:+<:~~·~:-.:·~;;·~~>!~'',~·"·:.:-::-~~::· ... "' '_.: . ·. ' ..... x.:~~~~.?-~i~~;.:.:~:·:,: :. • ' "I> :,'::1 ...... ,; 

could ··c0ntrol ·.'tbs oipher-wheEil msgneta in Bey relationahip a$~~·~-~~11 .. aet .. ~ .. ' 

upc.~:: '~/:r~tc¥~~4. · · · :·):;::-·· .. ~·:::~:::-:. · .. ··· · · · ·· . . .. ·'· . '.' . ;~·:. ' " ' . . .i: ' . : " 

. ··• · '.·4.~ · wt'ttt··a ·movement of' the eort 1nd1cated in plU'agraph· 5;: the'.·mqSm~ ~ "+ w .' ~ w .:~+;··~, : : : > • • -~=-::~·/-~:~-~:-:- : ' . . 

lengt!f.ot: tho ~·nctphering cycle tor each p0seible initial s•~tiJB ot :.the· t1Te· 

> r'.:,: ·, ·· .. ~.•-._' ' .·;·~·<·.: , .' ......_..,_ \. . '::'.~"~.:.: ... ·\:: ·. . , .'.' I 01i»¥r i . .wb&tla ;~an, by proper selection of' tape ob.arao:tera. "~~'( .. ~~ .. fjqual· to.~& _-: ~. :-. '. ":." . . . ·,:_~~~)\/.·~~~. ,;· . . . . • " .' . . ;! . 

t1m8•,the. l~~ ot the key tape. It the tape ls finite.·~ ~~~-h·_aii4 co~~leta ,,, 

,;. . ot· :~-~-.'~bi\io~~:~i•. the oyele would .the~ be 26,oOo iett.ir~~:·.f~:~¥.~~~.:~~~ere are.' 2af .' .. ~·:!i '\, ;;.. ·/,.; :·;:v:. • :j,, . ,.. . I 

. . :-.. :. 

.. "·:· 

.,. 

, .. 

' .. ~~~.:. 

. .;:-: . 

, .. . ...... 

-:• 

.. 

' ' .. :·; 

. ........ : .. · . · • . ! . 
REF ID:A52149B 

.\ 

poeaible initial settings or each ot the five cipher wheels 1 ... tho maoh.lae ~~J 

5 ~ould afford 26 enciphering cyclep eaoh 26,000 clui.ractera 1n length. 

5. ·There ia nothing in the. forae&aillfI which prevents the use.or any oi 

'· 

the variable tiictore .now avui.:Wble, el.lob as interchange of cipher •heels, wiring· 

ot the latter~ :'wiring ot le!t &nd rie.bt 1"1xed oequ.enc1es, eta·. 

G. There 13 110 reason -wey the ootoion or the tape sho11ld be limited to 

dieplaoeme~~s or a e1ngh• wheel at 11. U:ae; 1 t h perfectly possible that one, 

ho, threa, or even all five \"lb.eels aho...i.ld be aimu.ltuneol.lBl;y dhplaced, d.epen(li.ag 

~pon the perrnu.tation of veri."orations on the t'-11e vre:isentine itself at a g1wn, 

moment. Whether such a syatem of mu.l tiple displacemante \tOuld have aey a4:nintagee over that of single d1splaaements is not tij.lpLU"ent ut thie time. The poeeibility is merely mentioned for thu ebke of comphltenass of description. 

7. It 1a al so poe aib le t.h&t . two key tape e or di!f eront. length be \lsed. 

simtll.tnneously~ .in two transmitters, interacting to produce a latent reou.ltant 

running key. ae in the original A.~. & T. system. '.i'he tlisadva.ntngee from a or,ypto- [. 

graphic point of view 1u thiu oes@ are either entirely absent or, at moat, are 

not nearly e,o serious in consequence as \\'as the case in tbD original A.'r, & <r. 

system. 

a. t~ttached 1B bi ro11t;h sketch to cover the simple u.ee of one ke,y-tape 

tran111mitter "ne diecLUJsed above, p1.&r~graphe l to 6 inclusive. 

Attaohe_d: 

Ho11Bh sketch. 

W.itneesees 

Disclosed to us on iipril ;.lJ, 1932, 

at Wash io.gto n, D. C.; 

'dllic.m F. i'ri edman, 

Cr;1pta.11aly&~, 

otnoe of tho Chict Signal Officer. 

J~/vv&/..Ji._. 1900 F' Street, u .. ~,·., t;;ushington, TI. c. 

:Li:tAA-/1/.ii/~-f~,t/ 2121 Ue\li York Avenue. ~i. t ••• •tashington, D. c. 

atiaJ_~ ~J-v14,12 Chupin Streat, N. v.·. ,· Washington, 'P~ c. 

I 

/: 

t. 

· .. 

ii.-