REF ID:A363561 

This invention is an authenticating device and, pa.rticularl.Jr, is a. device by means of wt1ch the bona f'ides ot certain 

types of J:1Ss·aages can be readily prov-5d. 

It is customary in certain tields of c~rce, as for 

instance ba.nld.ng, to transmit cable a.nd radio com.unica.tions 

1n code or cipher, rather than in clear text. Thia is economical, and serves in same meas11re to protect the interests 

of eustoQors ar..d 0£ the coor.iercia.l institutions themselves. 

According to tho follo'Wing descript;ion, this invention is to 

be used by' ba."lldng a.nd other .financial. institu.-t.ions, but i.t . 

will be obvious tli..a.t it is applicable as well to other types 

of businesses, and has .military applications as well. 

In the drawings: 

· Figure 1 is a diagram of one ot tho nrlnng or 

"aera.mbling''elements used in the invention. 

Figure 2 is a diagramatic representation of 

the authentica.ting device 0£ this :i.m-ention. 

Tho invention comprises a group of ten mxing .iement.s 

1n the nature 0£ c:ryptograJiiic rotors.. One such rotor is 

•hmm in Figure i. where it may be sean to consist or a. body' 

member l.O, formed of Bakelite or solllll other insulating material,, 

and a. group of ten co:rt,acts U-20, inclusive. ::'-.. second group 

fl 

of contacts 21-.3~j am:ea.;son the opposito :race of the body 

member. 

'1'he cortacts 11-'.":0 will norm.all.7 serve as :input contacts 

and the other set will no~y serve, as output contacts. Connections between t!:'le sevural. input contacts and the output contacts are r.a.de at rand.om or accordilig to some predetermined 

campl.icatad rule. The result is, of course, that an inVtlt 

@'pproved for Release by NSA on 07-29-2014 pursuantto E.O. 1352a 

-1-

St/- S.S-J, 11 z_ 

· ·· 
•.. I, 

.,. 

REF ID:A363561 

•i&nal representing one condition ie converted to an outp...-t 

eigrnll repx~sonti:ng sooathiri..g entir~ different. 

Re:terrir.g to Figure 2, the :invention may be seen to 

include a she.rt. 3.5, imp}:orted at its two en.de in members 

38 and 39. The members 38, 39 rua.y be of any form desired. 

Their onl.T functions are to support the shaft 35, and to 

carry sta.tion!lr"J eJ..ectr!cal contacts 6 41-50, on the cne 

bal:ld, and 51...60., on the other.· 

lrounted on the Bhatt 35 are ten cryptographic rotors 

71-SOi such aa that illustrated in Figure l.,, and earlier deecribed. Tbe rotors a.re all essentia.lly •imilar. but their 

internal wiring normally lf:ill be different. The rotor:J bear 

on their peri}iteries ind:lcia of one type ·or another, the 

type depending,. to som exte~ at least,. ·on tho material to 

be handled by the .a.uthcntica.t':)r. In 'Figure 2$ rotors 7J. and 

72 and 74-00 bear ordiD;:LrJ .\r1.bi~ n"WBerals &rrl.nged in nomal.. 

order from O to 9. .Rotor 73 ca....""ries a,mbols ra:trese..-.f, ing the 

..,rxq ot Yarious countries. The rotors are, in additio:::i,. 

identified b7 number, as 81, or otherwise,. so that they can 

be readily arranged in a.fl1' desired order. ~ 

At the lett. end of the dmce or Figw. .. e r.> is a rotary 

switch 90 .tdapted £or manual operation, a.nd thit1 switch is in 

circuit with a. ~ttery 91 or other sou.rco ot current.. '!'here 

are six make contacts 92-C/7 on switch 90.- and,. i.t' desired, a 

mutral or non-make position 9S. The six. .cake· co."lta.cts a.re 

adapted for variable connection to t?-.:e ten contact-::? 41-501 

incl:wdve~ by aea.ns of plugs and jacks, as 99•, 99" • 

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REF ID:A363561 

At the oth<Sr end of the rotor system., ten out.ptJ.t leads 

sq be seen. and, o.ssocia.ted nth each,, an elbctric lam.p, as 

101 ... uo, inclusive, these lamps being likewise in the circuit 

of battery 91. Adjacent too lamps is a strip lll, bearing 

ten numerals randomly arr.~ngad. This strip is slida.bly 

.,-anted in a holder 112• so that it ma.7 be removed therei'roa 

and repl.a~d by anotr;er strip. 

In tht ireterred e:zbod:i.::ent o.r the invent.ion, a.eans are 

provided for stepping one or mre of t::-0 rot.ors 71-80 eaeh 

time a signal is .fed through the system. In Figure 2, such 

.mea.11s are :represented by block 120. Arter positioninz rota.ey 

Aitch 90,, switch 121, 'Which may be in the natu..""Ef oi a sillplo 

pa.ahbutton,, ia closed. !fuon it is reo~:ne~,, rotor 71 is ad-

'fanced one step.. The other rotors are stepped u."'lder tte 001~ ... 

trol ot l'Otor 71 in B:D."¥' ct several well-knom .ma.nr...ers. 

hsumin,g s?r.i.tch l2l to be cl.o~ed,, it ~ll be app;.u-ent 

that an electrical CUI-rent from batteriJ <J.l 'Will tra:veroe a. 

path through t'!le rotor syste;::--. depending,, 1n the .!ir:rt; irietance, on the input contact utD.ized, and, seeondl;y, upon 

the int..erm.J. :tlring of t~ several rct ors 1 tr.e order in which 

tm rotors a.re arr.e.nged on shaft. 35 • e.nd the relative rotato!7 

positions of ~he rotors. Under om set. of ccnditio:ns, for 

~le, a signal mtroduced at the contact 2 on the lefb.o.::t 

l"'Otor ot Figure 2 may find its my through the rotor ma2e to 

.energize lamp 110. A eha!'..ge in an;y one of the condft. ions 

mentioned just abov'l, may ca.use the signal to illuoi.D:lte 

lamp 101. The llU!:lbcr on f..h e strip lll, adjacent the enorgizad 

lamp, will depend upon the arr3.Dgerent of tie nu..rier.;,J.,s on tho 

•trip. 
REF ID:A363561 

l p.J 

One methoo of using t.1-ie ilr.rention, b7/bailk 'lr other 

.t.ins.ncial organization, will now be described. A United 

states bank,, wiahir;g to- make a ceposit in a !.oncbn bank, 

would compose the baeic text o:r its ~egr~ aeocl"ilne to 

the standard privo:t.e code in use. It. muld then t.ake tm 

device ot this invention and, in con.rorntit~,. with a prearr-anged plan, insert a particri.il.ar strip lll in the holder 

ll2 aud arrange the rotors in pt"OpGr order. The contacte 

92-Cfl. i:r.elusive, would next be plugged into p:"edetermined ) . 

input, connections in m3mber Jn. The rotors would then be 

individually adjUfited so th.:lt, for ~ple, (reading> 

eecond ro'tf or :lndicia on the rotora), the first two{fudica.t& 

f! 

the ~rie.:J.. numbe!' or the message {35, in Figure 2), rotQr 73 ~ 

I ;_/ 

j 

~ . 

indica.t(!) United States dollar.s, and rotors 74..,.so, the amount 

of t.lle deposit Ce9,756,;l25,, in the :lllustr:ttion)'. 

The operator nould then oove Pitch arm 90 to contact 

92, for example, nnd under these circumstances it 'ZiA1 be 

aasumed that tl'e lamp 102, adjace..'lt. l'lllreral 7 on strip lll, 

will be lighted. ."..rI:t 90 :would than bs lilO'Ved. to contact 931 

and lamp lOl a.djacer.t numeral 5 would be energised. Upon ,.: 

.movement of arm 90 to contact 94,. lamp 107, adjacs.i."lt numeral 

9, 1'0tll.d be energized. The operator would take these three 

mu:nerala in the order in 11bich thay occurred, namely, 7•5-9 $ 

and encode tmm by ::.ea."lS o.f his st.3.lldar·:: coc!e • thereb,- obi ·~ ta1n~ngfiroup such as RC7UP. This group* locat~d in a 

p:rearranged }X)sitio:"! in tho message, -.ould then be tra..'18- . 

aitted as an authentico.tor. 
REF ID:A363561 

'!'he be.fl.le ?"eceiving the eablegr:ltl would, after decoeing, 

set up 1to machine just a.s tre na.er,ine was set up b;r the transmitting bank, a...."Tar.ging the rotors in accordance with the amount 

o~ the deposit,, the serial number of the message, etc. The 

operator 110uld ne:r.:t .mov~ the switch am 90 or his device te 

th~ three contacts 92-93-94 in order. Unless he derived the 

namber represented in his codebook by the ·group ROXIP, he 

WOUld know th~t either tm message r-s not authentic or the.t 

eome error ha.d been ~de. 

Of course tre device will not ftrnish a different code 

group :tor eac."1 p;>ssible condition of the rotors and other 

nriable elements. Conaidering tl'Yl aeven rotor$ 104-llO 

alone,, it will be apparent that ten mill.ion different 

combinations can be set. up, whereas using the ten lamps,, 

101-UO, inclusive, in co.nlbin.~tions of three, only 720 diff'erent_ test groups can be obtained. A greater number of 

groups can, of .course, be achieved if it is- desired to use 

longer test groups, but in Ol'dina.?7 business usage the threentu:lercJ. group ha.s. been .round to be satisfactory. 

Further, it will be obvious that either more or .fe1"tr 

i~ rotors ma.y be usee, Without altering the principles of tr.e 

invention.. The number decided upon will depend upon maey 

factors. 

The above description is in specific terms. It ahould be 

understood, however, that the invention is not li'Dited to the 

exact structure ehown and described, and~ tberetore, for the 

true scope of the invention, reference should be. had to the 

appendeC. claims.. 

I claim: 

-s. 

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