US1484477A - Apparatus for ciphering and deciphering code expressions - Google Patents

Description

Feb 19, 1924. 1,484,477

A. G. DAMM APPARATUS FOR CIPHERING AND DECIPHERING CODE EXPRESSIONS Filed March 25. 1922 3 Sheets-Sheet 1 6 a 35 .55 V l Feb. 19 1924. 1,484,477

A. G. DAMM APPARATUS FOR CIBHERING AND DEGIBHERING CODE EXPRESSIONS Filed March 25. 1922 3 Sheets-Sheet 2 Feb. 19 9 1924. 1,484,477

A. (5. DAMM APPARATUS FOR cxraznnm AND nscnmazuue 0on2: sxrnnssxous F1106 March 25. 1922 s Sheets-Sheet a Patented Feb. 19, 1924.

UNITED STATES have; sesame Dana, ea Ramses,

arraaarcs FOR cIPHERIN'G Ann nncrrnnnrne coion experiences.

Application filed March 25, 1922. Serial no. 546,886.

To all whom it may concern:

Be it known that I, Anvil) GERHARD DAMM, a citizen of the Kingdom of Sweden, residing at Ronninge, Sweden, have invented new and useful Improvements in Appa a ms for Ciphering and Deciphering Code Expres sions, of which the following is a specification.

In commercial telegraphic correspondence code books are extensively used, by means of which commercial denominations, embracing one or several words or even complete phrases, may be rendered by one single abbreviated group of signs, usually comprising 4H5 letters or figures. The object of the codes published is to reduce the cost of telegrams. As a means of safeguarding the secrecy of messages such codes are ofno real practical value, being always available in theopen market for the translation of such telegrams into plain language. Even the use of a private code, which is kept secret, always implies a considerable risk, as the code must soon become known to a num ber of persons, and besides may be lost, stolen or copied, for instance photographic'ally, this often not being known to the correspondents until a considerable number of telegrams have been despatched. The numerous simple methods of a subsequent ciphering of the code expressions, hitherto applied in order to avoid such risks,have rarely proved satisfactory, a real security having been obtained only by continuously changing the principle of ciphering, aproced-ure which "at all events implies loss of time and frequent mistakes and errors.

According to the international telegraphic service regulations a group of 5 arbitrary figures or else a pronounceablc group of 10 letters is taxed as a unit. Oonseqeuntly a figure cipher telegram containing for instance 20 figures is taxed as 4 units of let'- ters each, while the same telegram, if trans lated into pronounceable groups of letters, will be taxed only as 2 units of 10 letters each,and the tariff expense will in the latter case be 5 0% of that in theformer. The object of this invention is to effect such a translation by mechanical operations of a kind to admit of a simultaneous and unequivocal ciphering and deciphering impenetrable to parties not concerned and of its imi'ne'diate recording in typeprint. This result, hitherto not obtainable by any known mechanical ciphering device, is made possible by the use of aspecial kind of letter groups comprising twosi'gns, oftwhich one is always a vowel and the other always a consonant, and bya special arrangement of the type-carrying members oi'tth'e apparatus"relatively to its members adj ustable in accordance with the signs to be translated.

This relation is schematically shownby According to the above twokinds of letter groups are usechco'nsisti'ng eith'or of avowel followed by a consonaiit or of-a consonant followed by a vowel, in whicll z'tily letter used must unequivocally oorrespond to one of the tenfigures. As't'he use :of'tenvowels is not permitted in international telegraph correspondence, certain vowels would have to correspoi'id to two figures, and coiise quenfl unequivocal deciphering would be impossible, if no possiibili'ty 'existed in each instance 'tci determine the casual meaning of a vowel "generally cciresponding te two figures. I I p Such a possibility does, however, "exist, twenty consonants telegraphically permitted being available as equivalents, which renders it possible always to translate fafigureby two 'difle're'nt consonants alternatively, so that on'e'of these consonants is used when the vowel adjoined has one of its figure meanings, and the other consonant, when the vowel in question has its other meaning;

In the above table the letter groups used are of the type 01b, in which it represents any one of five admissible vowels a, e,:-o',u,:y and b any one of the twenty admissible consonants lo, 0, d', f, g,h, j, k', 1, m, n, p, q, r, s, t, v, w, x, z. p

The scale of adjustment (key-board) for the ciphering is represented in the table by the two .double-figurecolumns A and B, and

the adjustment for ciphering of a certain figure is supposed to be effected by the .dis-

placement of the indicators represented by arrows to the left of each column.

The type-carrying members for recording the cipher, consisting in reality of type-- theindicators represented by arrows to the left of each letter column A,, B are brought.

into a position to point out the cipher sign resulting. As shown by the table, the vowel columns A and B contain the same five vowels, repeated twice in the same order, while each of the consonant columns contains ten diiferent consonants. The two vowel columns correspond to figure columns A and B, representing the type-carrying members, each of which contains five different figures, repeated twice in each column in the same sequence as in the columns containing theten figures and corresponding to the two consonant columns. 7

Supposing a couple of digits 73 is to be ciphered, the indicators to the left of the double'column B must be moved downwards, the left one by three steps and the right one by seven steps, which. according tothe above supposition efi'ectsan upward movement of the leftcolumn B by three steps, the indicator then pointing at letter e, and of the right column B by seven steps,

the indicator then pointing at letter (1, by

which operation the letter group eq is obtained as an equivalent of the figure group Supposing acouple of digits 28 is to be ciphered, the corresponding operations of adjustment will have to be performed within columns ,A, resulting in corresponding movements ofcolumns A, and in the cipher ek.

Thus in both these instances the firstfigure is rendered by letter e with a different sig-v nification in each instance.

By means of the table it will be shown, that the deciphering will give an unequivocal result. The reversed order of signs in the scale of adjustment and on the typewheels relatively to the columns, for ciphering is clearly shown by. columns 0, D and C D, respectively.

The deciphering operationswil-l be as follows: 1

As shown by .7 the arrows the indicators are adjusted for eq in columns D, which eflects a corresponding movement of columns the corresponding. column of the scale of adjustment, so that D, bringing the figures 73 into recording position, and for ek in columns C, which records 28 1110,.

VVhether' the one or. the

ciphering or the one or the other C, D for deciphering, will be obvious on account of the fact, that a group of figures or of letters v other of the we double columns .A, B has to be used for" can be found only within'one of those double 7 columns." g

If the ciphering operation is efi'ected by ciphering the first figure according to the right and the second figure according to the left column of double columns A and B, letteregroups of the type ha instead of ab will be produced.

If the series "of signs within A, B C and D are cyclically arranged, for instance as 7 types onthe circumference of wheels, it is evident that their initial positions may be arbitrarily varied relatively to each other and to the scale of adjustment. Consequently, as every single operation of ciphering may be considered either as an independent individual operation or as a member of continuous series of such operations, it is also evident that, when continuously ciphering, the relative initial positions can always be arbitrarily varied between two individual ciphering operations by the influence of some key-mechanism, for-instance by relating to a member, representing a. series of figures and movable in two different directions, according to the U. S. Patent ,No. 1,233,035. r V

In the accompanying drawings I have shown one embodiment of my invention- Fig. l'shows a front elevation of the apparatus, the one side of the cover being'removed. F ig.12 is a view from above with partofthe cover removed. Fig.3 is a section on line A-B in Fig. ,2. 'Fig. dis a section on line (3-1) in Fig. 1, and Fig. 5 the section last mentioned with some members in different positions. In Figs. 4 and 5 certain details are omittedin order to make the figures clearer. 1

In the drawings 1 indicatesabottom plate 1 V and 2' a cover formed with eight slots, "3,4, 5, 6, 7, 8, 9 and 10 (Fig. 2), in each of which a shde 11 having a lug 11 is movable. The

sides ofsaid slots are provided withnni- 1 said indicator slides actuates a 'lever- 12, 13, 1 1 15,16, 17,18, 19 respectively (Figs. 1, 4 and 5) by the lug 11 on each slide, each lever being fixed to a ratchet sector20, 21, 22,

23, 24, 25', 26, 27 respectively. These sectors are 'swingably journalled on a shaft 28 mounted in bearings 29, another sector 30, 31, 32, 33, 34-, 3 5, 36, 37 respectively being fixed to the hub of each ratchet sector. These sectors are attached respectively one to each of the ratchet sectors, to 13, 31 to 12, 33 to 22, 32 to 23, 34 to 17, to 16, 37 to 18 and 39 to 19, 33, 22 for instance being coupled 6 together by a tube, journalled on another tube coupling together and 23 and journalled in'its turn on the shaft 28. On the circumference of the sectors 3037, denominated typesectors, types are arranged in accordance with the columns A B C and D of the table mentioned above, so that the type'sector 30 corresponds to the right and the type sector 31 to the left column A the type sector 32 to the right and 33 to the left column B the type sector 34 to the right and 35 to the left column (1,, the type sector 36 to the right and 37 to the left column 1),.

Each ratchet sector is operated by a pawl 39, kept down by a spring 38 (Figs. 4 and 5), carried by the long arm of a lever 40, swingable on the shaft 28. Below the shaft 28 the levers 40 are provided with short arms 41, on which a bar 42 is fixed, rigidly connecting all levers 40 to each other. In starting position the ratehets engage the first tooth (farthest to the right in Figs. 4 and 5) of each ratchet sector. lVhen one of the indicator slides 11, for instance the second one from the left in Fig. 2, is moved for'instance to the seventh line of division of the corresponding scale, as indicated by dash lines in 4, the corresponding lever 13 and ratchet sector 21 partake of this movement, through which the pawl 39 is brought to engage the seventh tooth of the ratchet sector, counting from the right in Figure 4.

The type sector joined to the ratchet sector in question is hereby turned a corresponding angle, so that its seventh type from the right in Fig. 4 reaches a position perpendicularly above the centre of the shaft 28, which posi tion corresponds to that of a printing mechanism of a known kind (not shown in the drawings), by means of which a print of the type in question can be obtained on a paper band or the like. Before,however, said printing mechanism is broughtinto action, a further movement must be imparted to said type sector by means of its ratchet sector, the length of said movement being determined bv two cooperating members, each representing an arbitrary series of figures If a device for imparting such a variable movement were not used, the pronounceable letter cipher ob tained would become what is technically termed elementary, that is, a couple of consecutive figures, for instance 35, would invariably be translated for instance by up, while an additional and variable movement of the type sectors has the effect of rendering the ciphering result variable, so that said couple of figures will alternatively be trans lated for instance by up, ab, iq and so forth. It is well known that the variability of cipher during a period of arbitrary length is of the greatest importance as regards its resistance to analytic decoding by outsiders. As shown in the drawings the de vices for this purpose are as follows:

On the hub of a driving lever 43 an arm 44 is fixed, connected by an axle 45 (Fig. 3) to an arm 46 (Figs. 2 and 3), both members 43 and 46 swinging on shaft 28.

On the axle 45 nine arms 47 are swinging. The contour of these arms is circular and each is provided with a catch 48 and is extended on the other side of axle 45 as an arm 49, influenced by a spiral spring 50, attached to a rod 51, which connects the two arms 44 and 46. The catches 48 are adapted to actuate a fan-shaped member 52, which swings on the shaft 28 and consists of nine parts of the same shape and fixed together.

The nine parts of member 52 are displaced stepwise relatively to each other, each step corresponding to the division of the ratchet sectors, respectively to the distance between the types of the type-sectors. The curved arms 47 are, when in rest, kept in such a position by the springs 50, that when the driving lever 43 is turned down, all catches 48 pass the fan-shaped member 52 without actuating same, except one, which by the pressure of a key-member described below is kept down in spite of the action of its spring 50. The upper ends of the arms 47 are guided by slotted arms 55, swinging on an axle 53 and actuated by springs 54, which also serve to arrest the fan-shaped member 52 at the end of its movement. This latter member 52 is rigidly connected to the above-mentioned bar 42, which connects the shorter arms 41 of the levers 40 carrying the ratchets 39. The keymember referred to above consists in the embodiment shown of two disks 57, both fixed on an axle 56, the said discs 57 being connected by nine rods-58 (Fig. 2) placed at the same radial distance from the axle 56 and at the same peripherical distance from one another. Each of these rods 58 carries an adjustable roller 59, which, in a certain position of the disks 57, serves to keep one of the curved arms 47 pressed down (compare Fig. 3); The rollers 59 may be adjusted, relatively to each other and to the arms 47 influenced, in accordance with an arbitrary series of figures.

Supposing the key-member just described to be in such a position, that one of its rollers actuates an arm 47 corresponding to that part of the fan-shaped member 52, which in Fig. 3 is shown farthest to the right and which also is nearest to the guide arms 55 and farthest away from the catches 48, the turning downwards of the driving lever 43 will cause the arm 47 in question by its catch 48 to turn the member 52 an angle corresponding to one division of the ratchet sectors, the member 52 being at the end of this-movement arrested by theguiding arm v depressed by the arm 47 in question.

, If the key-member occupies such a position, that one of its rollers 59 is keeping down the second arm 47 from the right in Fig. 2, the member 52 will be turned an angle corresponding to two divisions of the ratchet wheels 60,61 are fixed with their teeth pointing in opposite directions, each wheel having nine teeth. Each of these ratchet wheels 60, 61 can be engaged by a pawl 62, 63 respectively. These pawls are linked to a cross bar 64 placed on a sliding rod 66 perpendicularly movable in a studand pressed'down by a spring 67. The pawls are attracted towards each other by a spring 68, and between them a roller '69 1s placed, said roller being disposed in a slot 70 (Fig. 2) in a sliding rod 71. At one end this rod 71 carries another roller 72, a spiral spring 73 pressing the'rod and said roller 72 against the links of a chain '74. As described in the-U. S. Patent No.

1,233,035 this chain is composed of flat links and segment-shaped ones arrangedin accordance with an arbitrary series of fig ures. When the roller 72 meets a flat link,

'the pawl 62 will engage the ratchet wheel 60, as shown in Fig. 3, whereas, when the roller 72 meets asegment link, the rod 71 is displaced to the rightinFig. 3, pawl 63 consequently engaging ratchet wheel 61. A.

knob on the sliding. rod 66 enters into a groove in ailever7 6. One end of said 1ever 7 6'turns on a journal in a support 75 and its other end is at the end of the. downward ,inovement of the driving lever 43 actuated by an arm 7 7 fixed thereto, this causing the sliding rod 66 to move upwards against the spring 67 ,so that either of the pawls 62=or 63 momentarily engaging its ratchet wheel can engage a new tooth of .that ratchet wheel. When the driving le- 'ver 43 is then turnedback into its idle po sition, the key-member will, on account of the downward action of spring 67 on the pawl-mechanism described, turn one step in one directionor the other, the direction depending upon the momentary position of the chain 74.

' This chain is 'moved a distance corresponding to the length or one link by each] downward movement of the driving lever r 43. .At the end of each such movement. a

protrudingpart 78 of said lever '43 actuates one of the arms of a double-armed lever 80, journalled in bearing 79, its other arm being pivoted toa bar 81, connected by a universal coupling 82 to a sliding rod 83,

'which is pivoted to a double-armed lever 84 (Fig. 2), swinging on the axle 85 ofa ratchet wheel 88 fixed to a prism 86 driving the chain 74.

Said double-armed lever 84 carries: a pawl 87 engaging the ratchet wheel 88. When the arm to the rightin 30f lever; is pressed down by the portion 78 of the driving lever 43 and the rod 83; is pushed to the right in Fig. 3, which movement corresponds to an upward movement in Fig. 2,

the pawl 87 will turn the ratchet wheel 88 such an angle that the chain. 74 moves the length of one link. lVhen the driving lever 43 is turned upwards, a spring (not shown on the drawings) moves the sliding bar83 so far downwards in Fig. 2 that the pawl 87 engages the next tooth of the wheel 88.

ratchet In order to return the ratchetand type- I sectors into their idle positions the following device is provided. On the shaft 28 are journalledtwo arms 89 (Figs; 1-and 5),

rigidly connected to each other by a rod 90, which by a spring 91 isjpressed against the ratchet sectors When the driving lever 43 is turned upwards from the position shown ice in Fig. 5, the arms 44 and 46 (Figs. 2and 3) turn to the left in Fig.- 8, in which movement the bent arms 47 partake, one'of these 7 having, as described above, at an earlier moment turned. the fan-shaped fmember 52 to the right in Fig. 3. This member'52, connected by the bar 42 to the doublesarmed levers 41,40, which carry the pawls 39, will then be turned to the left in. Fig. 3 by the spring 91, which forces. all '-ratchet-' and type-sectors back to their starting position.

Each o fthepawls E39 isprovided with an.

arm 92 (Fig. 4), having at its lower enda recess 93, one side-oi which is slightly rounded. Said arm 92 enters between two parallel arms 95, rigidly connected to each other and pivotally connected to a fixed support-94, a pin 96 or the like being fixed in said arms.

By a'link 97 the arms 95 are connected'to an arml98 pivotally connectedto the support 94 and actuated by a spring 99 tending to lift thearm .98. All arms 98 are con-' nected together by a rod 100, which also serves to connect the links 97 and the arms 98 and which, when lifted by the action of the spring 99, presses against a stop 101 se cured tojthebase plate 1.

Before those ratchet sectors, the type-sectors of which have occasionally been adjust ed for enciphering or deciphering, come backi'nto their position of rest, the arms 92 of their pawls 39 will engagethe corresponding pins 96', thus, as the movement continues, disengaging the pawls 39 from their ratchet sectors 20. Just before these ratchet sectors, respectively the arms 89, reach their idle position (Fig. 4) a projection 102 of each arm 89'will force the rod 100 down wards, this movement being transmitted to thearms 95 and the pins96 by means of the links 97. The pins 96 now engage the recesses 93 of the pawlarms 92, which latter again engage the ratchet sectors 20;

When a group of figures, for instance 353567 is to be ciphered, the operations and their results are as follows, it being supposed that the initial positions and arrangement of the chain 74 and the revolvingkey member are as shown in Fig. 2, a roller 59 pressing down the fourth lever 47 from the left. According to said drawing the revolving key member represents, if rotating in the direction determined by a high link of the chain74, a series of figures 6, 2, 5, 8, i, 1, 7, 3, 9, each figure of which equals the number of steps of additional movement given to the sectors by means of the fanshaped plate 52.

It should be noted that the slides during the first step of adjustment will not actuate the sectors, as is evident from Fig. 4.

When ciphering, which always comprises two figures, the adjustment for the second figure is first made, thus in this instance the first indicator from the left on 5, the second indicator from the left on 3, by which operation the type sector 31 is not turned, while the type sector 30 is turned seven steps. Then the driving lever 43 is pressed down, this movement bringing a high link of the chain 74 to bear against the roller 72 and turning, by the action of the sixth lever 47 from the right on the fan-shaped plate 52, the type sectors six steps. At the end of the downward movement of the driving lever the type sector 31 thus has been turned six steps while the type sector 30 has been turned thirteen steps. The types of these sectors being in printing position thus are y and k respectively, which letters will be recorded as k y. Nhen returning the driving lever 43, the pawl 63 (Fig. 3) will turn the revolving key member so as to make a roller 59 press down the second lever 47 from the right in Fig. 2. The next ad justments of the indicators are the same. The downward movement of the driving lever, which brings a new high link into operative position, will move the sectors two steps, bringing into printing position u and 0, recorded as c u.

The next adjustments will be: the third indicator from the left on 7 and the fourth on 6, turning the type sectors 33 and 32 three: and four steps, respectively. As the additional mo-vement'caused by'the downward movement of the driving lever 43 will befivestepsthe types 0 and p of the type sectors will come into printing position" and will be recorded as p 0.

Thus the figures 353567 will be ciphered as ky cu po.

In order to decipher this code word, the revolving key member and the key chain are placed in the same initial positions as used for the ciphering.

The adjustments will be: the sixth indicator from the-left on k and the fifth indica tor from the left on y, turning the type sectors 34 and 35 seven and four steps respectively. The additional movement imparted by the fan-shaped plate 52 Will be six steps, bringing the types 3 and 5 respectively'into printing position to be recorded as 35. When returning the driving lever, the pawl 63, (Fig. 3) will turn the revolving key member so as to make a roller 59 press down the second lever 47' from the right, in Fig. 2. The next adjustments will bez'the sixth indicator from the left on e and the fifth indicator from the left on u, turning the type sectors one and three steps respectively. The additional movement of these sectors caused by the fan-shaped plate will be two steps, bringing the types 3 and 5 into printing position, recorded as 35. The movements of the driving lever have then brought a new high link of the chain and a roller of the revolving key member to press down the fifth lever 17 from the right or left into active position. The next adjustments will be: the eighth indicator from the left on p and the seventh indicator from the left on o, turning the type sectors 36 and 37 one and two steps respectively. The additional movement is five steps, thus bringing the type 6 of the type sector 36 and the type 7 of the type sector 37 into printing position, to be recorded as 67.

Thus the code word ky cu p0 has been deciphered into the original sequence of the figures 353567.

Having now described my invention I declare that what I claim is In an apparatus for recording in typeprint two-letter syllables, always composed of one vowel and one consonant and constituting cipher-equivalents of two-figure groups, and for the rendering in type-print two-figure groups, constituting cipher-equiv alents of two-letter syllables of said kind, the combination of a scale of adjustment, one part of which, for the ciphering of twofigure groups, comprises four series of figures, two of these series containing ten different figures in arbitrary order and the other two series containing each five figures in arbitrary order, these figures being different in one series as compared to the other,

and the other part of which scale, for the ciphering of two-letter syllables, comprises four series of letters of which series two contain each ten different consonants in arbitrary orderandthe two'- other both contain the same arbitrary sequence of five vowels,

and eight rotary type-wheels' four carrying letter-types and four figure-types, of Whioh type-wheels; those carrying letter-itypes: are dependent, as'to their movements, each on a member adjustable according to one of the four series of figures of thescale of adjust ment, the arrangement of .theiletter-types beingsuch, that, the twof type-wheels dependent each fon a member adjustable according to the'series'of ten figures carry each ten consonant-types, for each wheel the same as are comprised in one of the series of ten consonants of the scale 0r adjustm'ent,'

though in reversed order, and that the two type-wheels, which are dependent each one member adjustable according to one of the 'Series of five figures, carry the same five vowel-types repeated twice in the same sequence on each type-wheel and for each type-wheel in reversed order, as compared the scale of adj ustment, th'effour type-wheels carrying figure types being dependent as' to their movements eachi'on a member to that of one of the series of five vowels of,

adjustable according to the 1 letter-series of the scale of adjustment, the arrange-l V merit of the fi ure-types'being suchfthat the two't'ype-w eels, 'eachof which is de pendent on a, member adjustable according' to one of the series containing ten consonants, both carry the same figure-types, i

for each wheel in reversed order as compared to that of one of the ten-figure series of the scale of adjustment, and that thetwo those of one ofthe fi'veffigure series of the 7 scale of adjustment, but 1 arranged in re-:'

versed order. 7 I .v In testimony whereof I have signed'my name 7 j r i Anv l eERHARnDAMM

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