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REF ID:A36355B 

Patented Au0 • 15, 1950 2 518 458. 0 ' ' 

UNIT.ED 

l 

STAT.ES PATENT 

2,518,45,8 

AIJTHEN.TICATING DEVICE 

William F. Fril}dinan, Washington, D. C. 

Application.August 25; 1944, Serial No. 551,172 

1 Claim. (CI. 35-4) 

(Granted nndel' the act of· !\larch 3, 1883, as am.ended A11ril 30, 1928; 370 Q. G. 757) 

OFFICE 

2 

The invention described. herein may. be manu- to be handled by the authenticator. In Figure 2, 

factured and used by or for the Government for rotors 11 and i2 and" 14-80 bear ordinary Arabic 

governmental purposes, without the payment of numerals arranged in nor1nal order from· O to· 9. 

any royalty thereon. Rotor 13 carries symbols representing the money Thi~ in:vention.is an authentica-ting device and, O of various countries. The rotors a.re, in additon, 

particularly, is a. device by means. of which the identified by numbe1·, as 81, or ot..."lerwise, so· that 

bona fl.des of certain types of messages can be they can be readily arranged in any desired order. 

readily proved. At the left end of the device of· Figure 2 is a It is c.ustomary: in certain fields of commerce, rotary switch !iD adapted for manual operation, as for instance banking, to transmit ca!Jle and ·.10 and this swltch is in circuit with a battery 91 or radio communications in code or cipher, rather other source oJ current. There are six make con- than in clear text. This is economical, and serves tacts 92-91 on switch 90,.and, if desired, a neutral 

in some measure to protect the interests of cus- or non-make position 93. The six make contacts 

tomers and of the commercial institutions them- are adapted for variable connection to the ten 

selves. According to the· following description, .J.I contacts 41-50, inclusive, by means of plUgs and 

this invention is to be used by banking and other jacks, as 99', 99". 

financial institutions, but ii will be obvious that At the other end of the rotor system, ten· output 

it ls applicable as well to other types of businesses, leads may be seen, and, associated with each, an and has military applications as well. electric lamp, as 101-1 liJ, inclusive, these lamps 

In the drawings: 10 being likewise in the circuit of .battery g I. AdjaFigure 1 is a digaram of one of the mixing or cent the lamps is a strip 111, bearing ten nume1·a1s 

"scrambling" elements used in the invention. randomly arranged. This strip is slidably mountFigure 2 is a diagrammatic representation of ed in a holder I 12, so that it may be removed 

the authenticating device of this invention. therefrom and replaced by another strip. 

The invention comprises a group of ten mixing 25 In the preferred embodiment of the invention, 

elements in the natw·e. of cryptographic rotors. means are provided for stepping one or more of 

One such rotor is shown in Figure 1, where it may the rotors 11-80 each time a signal is fed through 

be seen to consist of a ·body member I 0, formed of the system. In Figure 2, such means are repreBakelite or some other insulating material, and sented by block I 2El. After positioning rotary a group of-ten contacts 11-20, inclusive. A sec- 3o switch 90, switch 121, which may be in the na- ond group of contacts, 21-30, appears on the op- ture of a simple pushbutton, is closed. When 

posite face of the body member. it is reopened, rotor 11 is advanced one step. The 

The contacts 11-20 will normally serve as input other rotors are stepped under the control of 

contacts and the other set will normally serve as rotor 11 in any of several well-known manners. output co11tacts. Connections between the sev- 35 Assuming switch 121 to be closed, it will ·be aperal input contacts and the output contacts are parent that an electrical current from battery 91 

made at random or according to some predeter- will traverse a path through the rotor system demined complicated rule. The result is, of cow·se, pending, in the first instance, on the input con- that an input signal representing one condition is tact utilized, and, secondly, upon the internal 

converted to an output signal representing some- 40 wiring of the several rotors, the order in which 

thing entirely different. the rotors are arranged on shaft 35, and the relaReferring to Figure 2, the invention may be tive rotatory positions of the rotors. Under one seen to include a shaft 35, supported at its two set of conditions, for example, a signal introduced 

ends in members 38 and 39. The members 38, 39 at the contact :! on the leftmost rotor of Figure 2 

may be of any form desired. Their only func- 45 may find its way through the rotor maze to ener- tions are to support the shaft 35, and to carry gize lamp 110. A change in any one of the con- stationary electrical contacts, 41-50, on the one ditions mentioned just above, ·may cause the sighand, and 51-60, on the other. . nal to illuminate lamp IOI. The number on the 

Mounted on the shaft 35 are ten cryptographic strip 111, adjacent the energized lamp, will derotors 11-80, such as that illustrated in Figure 1, 50 pend upon the aITangement of the numerals on and earlier described. The rotors are all essen- the strip. 

tially similar, but their internal wiring normally One method of using the invention, by a bank 

will be different. The rotors bear on their periph- or other financial organization, will now be deeries in1icia of one type or another, the type de- scribed. A United states bank, wiShing to make 

pending, to some extent at least, on the material iii a deposit in a London !;lank, woU!d compose t!:le 
REF ID:A36355B 

3 

basic text ot its cablegram according to the standard private code in use. It would then take the 

device of this invention and, in conformity with a prearranged plan, insert a. particular strip 111 

4 can be set up, whereas using the ten lamps, fG 1-

110, inclusive, in combinations of three, only 720 

diiferent 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 ordinary business usage the three-numeral group has 

been found to be satisfactory. 

Further, it will .be obvious that either more or fewer rotors may be used, without altering the 

principles of the invention. The number decided 

upon will depend upon many factors. 

in the holder 112 and arrange the rotors in 5 

proper order. The contacts 92-97, inclusive, 

wouid next be ;plugged into predetermined input 

connections in member 38. The rotors would 

then .be individually adjusted so that, for example 

<reading the second row of indicia on the rotors), 10 

the first two would indicate the serial number of 

the message C35, in Figure 2), rotor 13 would indicate United States dollars, and rotors 14-80, 

the amount of the deposit ($9,756,125, in the illus-

.tra.tion> • The operator would then move switch arm H to 

contact 92, for example, and under these circumstances it may be assumed that the lamp I 02, adjacent numeral 1 on strip 111, will be lighted. 

Arm 90 would then be moved to contact 93, and 20 lamp I 0 I adjacent numeral 5 would be energized. 

Upon movement of a.rm 90 to contact 94, lamp 

The above description is in specific terms. It 

shouid be understood, however, that the invention is not limited to the exact structure shown 

15 and described, and, therefore, for the true scope 

of the invention, reference should be had to the 

appended claim. 

I 01, adjacent numeral 9, would be energized. The 

operator would take these three numerals in the 

order in which they occurred, namely, 1-5-9, and 21 encode them by means of this standard code, 

thereby obtaining a group such as ROXIP. This 

group, located in a prearranged position in the 

message, wouid then be transmitted as an au- thenticator. ao 

The bank receiving the cablegram would, aft- er decoding, set up its machine just as the ma- chine was set up by the transmitting bank, ar- ranging the rotors in accordance with the amount 

I claim: 

In a device of the nature described, a source of current, a series of crytographic motors having a plurality of inputs and a plurality of outputs, a selector adapted to make successive circuits between said source of current and a limited nwn- ber of preselected inputs to said series, an indicator for each of said outputs adapted to be ener- gized by said source, and means for assigning 

variable values to said indicators said msa.ns com- prising a holding member adjacent said indicators and a card or the like slidably held thereby said ca.rd bearing indicia which may be variously 

juxtaposed with the said indicators. 

WILLIAM F. FRIEDMAN. 

REFERENCES CITED 

of the depasit, the serial number of the message, II The following references are of record in the 

etc. The operator would next move the switch fil th arm 90 of his device to the three contacts 92-93- e of is pa.tent: 

94 in order. Unless he derived the number represented in his codebook by the group ROXIP, he UNITED STATES PATENTS 

would know that either the message was not .

40 Number 

authentic or that some error had been made. 1,584,660 

Of course the device will not furnish a dif- 1,683,072 

ferent code group for each possible conditio1,l of 1,938,028 

the rotors and other variable· elements. Consid- 1,953,829 

ering the seven rotors I 04-110 alone, it will be . 45 2,080,416 

apparent that ten million di.trerent· combinations 2,139,676 

Name Date 

Scherbius ---------- May 11, 1926 

Hebern ------------ Sept. 4, 1928 

Korn -------------- Dec. 5, 1933 

Morris --------------Apr. 3, 1934 

Friedman ---------- May 18, 1937 

Friedman ---------- Dec. 13, 1938