Improvements in Cryptographic Instruments.
Year: 1891

page_text: Date of Application, 11th July, 1891
Comp.ete Specification Left, 11th Apr., 1892-Accepted, 21st May, 1892
PROVISIONAL SPECIFICATION.
Improvements in Cryptographic Instruments.
I, RICHARD HARTE of 1, Chatsworth Villas, Croydon, in the County of
Surrey, Journalist, do hereby declare the nature of this invention to be as
follows:
My invention relates to an improved cryptograph or instrument for composing:
and translating communications in cipher in accordance with any arbitrarily
selected, collocation of letters, word, or sentence of indefinite length adopted as
a key.
The instrument may comprise one or several similar elements in combination,
each element consisting essentially of two or more alphabetical series of letters
and corresponding indexes 80 combined and arranged for operation with regard to
each other, and provided with. such facility of preliminary adjustment with regard
to any predetermined key letter that the key.letter, the letter to be.disguised, and
the corresponding, cipher letter, may be said. to be mutually reciprocal, that is to
say that from any two of these the third may always be found so that the
instrument may be used in precisely the same manner whether for composing or
translating a cipher message.
Each series of letters may comprise more than one complete alphabet and may+
be in alphabetical or inverted alphabetical order, as may be necessary (according
to the relative operation of the parts) for the purpose of using the instrument in
the same way indifferently for composing and translating a cipher message and the
form and arrangement may be straight or circular or a combination of the two,
according as the parts of the instrument in which the invention is embodied are
constructed to receive rectilinear or rotary motion.
In the rectilinear form of instrument a relatively fixed alphabetical series of
letters and a movable index are combined with a relatively movable series and a
fixed index, the one series and the index of the other being constant with regard to
each other, whilst the other series and the index of the first are capable of being
set or adjusted with regard to each other and to the first series, according to the
key letter selected.
The movable members of this combination are fitted to work alongside, above,-
or-beneath, the relatively fixed members and are adjusted by a rectilineal sliding
motion with reference thereto.
By arranging any number of such elements side by side, a cryptographic instru-
ment is produced which may be conveniently used in connection with a -key-word
or sentence of any length.
In the rotary form, discs are used either superposed or juxtaposed with regard
to each other.
In the superposed form, the discs and indexes are relatively revolvable about a
common centre, the discs bearing the respective series of letters on their marginal
faces and being of different diameters in order that the circles of letters on the
underlying diso may be read off beyond the edge of the disa or discs above.
In one of the juxtaposed forms the discs instead of being concentric are revolv-
able about different centres, the discs being geared together so as to be revolved:
the one by the other with regard to fixed-indexes, one of the discs being adjustable.
about its centre independently of the other, in order that it
may-b
be set in accord:
ance with the key letter prior to manipulation of the disos for translating the
original letter into the cipher letter, or vice versa.
For convenience in combining a number of such elements within a small compass.
to form a complete cryptograph, the disce may bear the series of letters on their

page_text: edges and instead of turning on different centres they may be concentric and be
combined or geared so that rotary motion of the one will produce.a. corresponding
motion of the other relatively to their corresponding indexes, means being provided
whereby they may be readily set with regard to any given key letter.
Another form of instrument consists in a combination of the sliding with the
rotary form in which the one series of letters is borne on the face or edge of a disc
and the other upon a sliding strip the disc and strip being geared together so that
rotary motion of the one will produce rectilineal motion of the other and rice versa
and each being movable relatively to an index, means being provided as before
whereby the series of letters or the indexes may be set in accordance with
any given key letter determining the relation between the original and cipher
letters.
Dated this 11th day July 1891.
.
COMPLETE SPECIFICATION.
Improvements in Cryptographic Instruments.
1, RICHARD HARTE of 1, Chatsworth Villas, Croydon, in the County of Surrey,
Journalist, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
•
My invention relates to an improved cryptograph or instrument for translating
communications into and out of cipher in accordance with any arbitrarily selected
collocation of letters, word, or sentence, whatever of indefinite length, adopted as a
key. The instrument may comprise one element or preferably several similar
elements in combination, each element consisting essentialy of two or more alpha-
betical series of letters or signs and corresponding indexes so combined and arranged
for operation with regard to each other and capable of such preliminary adjust-
ment with regard to any predetermined key letter that the key letter, the letter to
be disguised or translated and the corresponding cipher letter, may be said to be
mutually reciprocal, that is to say that from any two of these the third may always
be found so that the instrument may be used in precisely the same manner whether
for translating a message into or out of cipher. Each series of letters may comprise
more than one complete alphabet and may be in alphabetical or inverted alphabetical
order, as may be necessary (according to the relative operation of the parts) for
the purpose of using the instrument in the same way indifferently for translating a
message into or out of cipher and the arrangement of the alphabets may be either
straight or circular or a combination of the two according as the parts of the
instrument in which the invention is embodied, receive rectilinear or rotary
*. motion.
In the rectilinear form of instrument each element comprises a relatively fixed
alphabetical series of letters and a movable index in combination with relatively
movable alphabetical series and an index which is adjustable but remains stationary
when the instrument is in use, the movable series and the index of the first-
mentioned series being constant with regard to each other and moving together
whilst the index of the movable series is capable of being set or adjusted with
regard to the fixed series so as to determine the relation of the movable index and
the fixed alphabet according to the key letter selected. The movable members of
this combination are fitted to work alongside, above, or beneath, the relatively-fixed
members and are adjusted by a rectilineal sliding motion with reference thereto.
By arranging any number of such elements side by side, a cryptographic instrument
is produced which may be conveniently used in connection with a key-word' or
sentence of any length

page_text: In the rotary form, discs are used either superposed or juxtaposed with regard
to each other. In the superposed form, the discs and indexes are relatively revolv-
able about a common centre, the discs bearing the respective series of letters on
their marginal facos and being of difforent diameters in order that the circles of
letters on the underlying disc may be read off beyond the edge of the disc or discs
above. In one of the juxtaposed forms the discs, instead of being concentric are
revolvable about different centres, the discs being geared together so as to be revolved
the one by the other with regard to fixed indexes, one of the discs being adjustable
about its centre independently of the other, in order that it be set in accord-
may
ance with the key-letter prior to manipulation of the discs for translating the
original letter into the cipher letter, or vice versa. For convenience in combining a
number of such elements within a small compass to form a complete cryptograph,
the discs may bear the series of letters on their edges, and, instead of turning on
different centres, they may be concentric and be combined or geared so that rotary
motion of the one will produce a corresponding motion of the other relatively to
their corresponding indexes, means being provided whereby they may be readily
set with regard to any given key-letter.
Another form of instrument consists in a combination of the sliding with the
rotary form in which the one séries of letters is borne on the face or edge of a
disc and the other upon a sliding strip, the disc and strip being geared together so
that rotary motion of the one will produce rectilineal motion of the other and
vice versa and each being movable relatively to an index, means being provided as
before, whereby the series of letters on the indexes may be set in accordance with
any given key letter determining the relation between the original and cypher
letters.
Reference is to be had to the accompanying drawings, forming part of this
Specification, wherein Figures 1, 2, and 3 are three plan views of the simplest, or
reotilinear, form of instrument, the parts being in different positions. Figure 4.is
a cross-section on line 1-1 Figure 1. Figure 5 is a front elevation (the base
board being in section). Figure 6 is a sectional elevation, (on line 1-1 Figure 7)
and Figure 7 a sectional plan, of a combined rotary and rectilinear form of instrument.
Figure 8 is a plan of another instrument of the same kind. Figure 9 is a plan of
a rotary form of instrument in which the discs are superposed. Figure 10 is a plan
of another rotary form of instrument in which the discs are juxtaposed and geared
together. The same letters of reference indicate similar parts, or parts performing
similar functions, in all the figures.
Figures 1 to 4 illustrate an instrument comprising only three elements of which
it will be understood the number is capable of unlimited extension, according to the
length of the key word or sentence to be adopted. As here arranged, each element
comprises a stationary strip A bearing an alphabet over or alongside of which
works a sliding index a carried by a sliding strip B bearing two complete alphabets,
here shown as arranged consecutively, although consecutive order is by no means
necessary, provided that the instruments used for translating into and out of cypher
are identical. In the arrangement shewn, although the alphabets A and B are similar
in the order of their letters, the effect produced by the arrangement of indexes and
alphabets is as though the alphabets wore in inverse order to each other. b is the
index of the alphabets B. It is carried by a slide C to permit of its adjustment
according to the key-letter selected and remains stationary after being so set.
Thus B and a move together and are constant with regard to each other, whilst b is
adjustable with regard both to A and to B so that the indication given by the
one index will vary according to the adjustment of the other index. Of course it
will be understood that alphabet A might be adjustable and index b fixed or a and B
might be adjustable with regard to each other and A and b be fixed. The slides B
and C are fitted to slide in grooves in the base board of the instrument, and
have knobs or handles by which they may be easily moved.
The instrument may be used as follows:-Suppose the word "REX" to be
selected as the key, the several indexes bare to be set to the several letters of the

page_text: key-word after all the slides B have been pushed up to the top or drawn down to
the bottom, or arranged in any other preconcerted position. In Figure 1 they are
all shewn with the indexes a placed at the initial'letter of the alphabets A and the
indexes b set to the letters of the key-word "REX" Suppose the word to be
translated into oipher to be "WAR," this may be done by bringing the several
indexes a to the several lettors of that word on the alphabets A, as in 'Figure 2,
whereby the alphabets B are so shifted as to bring the several letters "VEG
opposite the several indexes which letters are the ciphers corresponding to the word
to be transmitted. To retranslate this cypher word, the recipient, having set the
indexes b of his instrument to the key-word "REX," brings the indexes a to the
cipher letters "VEG" and reads off the message "WAR" at the indexes b, as
shewn in Figure 3. Or the functions of a and b may be varied, by setting the
indexes a to the key word for translating into cipher and setting the indexes 6 to
the word to be translated and moving all the indexes a up to the top of alphabet A
and reading the cipher at indexes b, the operation being similar but reversed in
retranslating from cipher into ordinary language.
Referring now to Figures 5, 6, and 7, A are sliding strips, each carrying an
alphabet,, as before, of which the letters are set by reference to index apertures a
in a cross-bar beneath which the strips slide and B are discs mounted side by side
and rotated about a common axis D. For this purpose each disc is mounted
friction tight upon a sleeve e lcose on the axis D and carrying a toothed pinion E
with which gears a sliding rack rod F forming a continuation of the corresponding
alphabet strip A. Each disc B bears an alphabet on its periphery the lotters of
which are read off by reference to index apertures.b in a bar C. It will of course
be evident that pointers might be used instead of the index apertures a and' b.
The adjustment of the several discs B, by which the relation of their alphabets' to
those of the alphabets A is varied according to the respective letters of the key-
word, is provided for by the friction tight connection of the discs B with their
pinions which admits of the discs being turned independently of the pinions for
the purposes of this adjustment, whilst ensuring the turning together of. the discs
and pinions when operated by the strips A. Or, instead of the friction-tight con-
nection of the discs and pinions they might be fast with each other and the adjust-
ment provided for by temporarily ungearing the racks F from the pinions E by
any suitable contrivance, for instance by withdrawing wedge strips G from the bed
of the grooves in which the rack rods slide, to admit of the latter being depressed.
As in the first described case, the instrument illustrated comprises only three
elements but their number may he increased indefinitely, according to the length
of the key word, or if the key-word or sentence contain more letters than there
are elements in the instrument the same elements may be reset to the remainder of
the key word or sentence after being used to translate the part of the message
corresponding to the first part of the key-word or sentence.
Referring now to Figure 8, there is only one sliding alphabet strip A with its
index aperture a and rack F which gears with teeth on the periphery of an alphabet
disc B bearing two alphabets arranged consecutively around its marginal face,
visible through an index aperture 6 in a disc C concentric with disc B and adjust-
able about its centre. In this case the relation of A to B is constant and the
adjustment to the letters of the key-word or sentence is effected by previously
turning disc C to the corresponding key letter each time the slide A and disc B
are moved. For this purpose dise C has an additional index aperture i which is
set by reference to a stationary alphabet I.
Referring to Figure 9, the alphabet A is on the stationary base plate and its
index aperture a is movable over it being formed in a disc B turning on its centre
concentrically with alphabet A and carrying two complete alphabets, as before.
This disc is covered by a disc C. which has an index aperture 6 which discloses the
letters of the alphabets on disc B. Disc C also: has an index aperture working
over another fixed alphabet I on the base board. The mode of using this instru-
ment is similar to that last described, in respect of successively setting the index i

page_text: to the several letters of the key, and in both cases the functions of the alphabets A
and I may be reversed.
Referring to Figure 10, A B are two alphabet toothed discs geared together and
working under index apertures a b, the adjustment to the key letters being effected
by mounting one of the discs, say A, upon a boss J pivoted on an eccentric axis j
so that by turning the boss J the discs may be ungeared for resetting. It will
however be obvious that each of the single-element forms of the instrument,
although cheaper to make, is less convenient to use than the first two forms
described, both by reason of the constantly upright position of the letters and the
facility for combining a number of elements in one instrument afforded by the
first described forms.
Reverting again to Figure 5, it will be seen that by coupling the discs B in
pairs, friction-tight to admit of setting to the key letters, the sliding alphabets A
aud the rack and pinion gear might be dispensed with, each alternate disc B and
its index b then fulfilling the function of sliding alphabet A and its index a, for
bringing the other disc B, with which it is coupled, to the position determined by
the key-letter adopted and the letter to be translated.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I
claim is-
1. A cryptograph or instrument for translating communications into or out of
cypher, whereof each element consists of a combination of a sliding and a stationary
alphabet and of their respective indexes adjustable or movable with regard thereto,
for operation and use substantially as specified."
2. A cryptograph or instrument for translating communications into and out of
cipher, whereof each element consists of a combination of a slide and disc geared
together and of their respective alphabets and indexes, arranged for operation and
use substantially as specified.
3. In an instrument of the combined slide and disc form, making the disc and
slide adjustable relatively to each other, for the purpose of setting to the key-
letter, substantially as specified.
1
4. The respective cryptographic instruments constructed and arranged for
operation and use substantially as herein described with reference to the respective
figures of the drawings.
1000