An Improved Apparatus for Use in Cryptographic Writing.
Year: 1894

page_text: Date of Application, 4th Jan., 1894
Complete Specification Left, 4th Oct., 1894-Accepted, 24th Nov.. 1894
PROVISIONAL SPECIFICATION.
An Improved Apparatus for Use in Cryptographic Writing.
JAMES WILLIAM NOBLE 26 Pepys Road South, New Cross S.E. Electrician
do hereby declare the nature of this invention to be as follows:-
My invention consists in an apparatus for cryptographic purposes having the
following advantages, vizt. :-1. Compactness. 2. Simplicity in construction and
working. 3 Rapidity of translation into or out of cipher. 4 The key may consist
of any word or words or arbitrary combination of letters or figures. 5 Impossibility
of deciphering by outsiders. 6 Terminating syllables of words, or suffixes, may be
put into single cipher.
The apparatus consists of (1) a circular disc with a central axis which can be
rotated in either direction by any ordinary method. This I call the "cipher
disc"; its margin is divided into a number of equal spaces to contain the letters,
figures or other marks constituting the cipher code. The cipher code may however
occupy an aliquot part only of the margin, in which case it must be written again
in the other part of the margin. The disc carries a pointer which moves as the
dise is rotated, and the end of which extends beyond the circumference of the disc.
This pointer is an important feature of the invention, and its use will be hereafter
explained. (2) An exterior fixed ring whose inner circumference coincides with the
circumference of the cipher disc. The ring has as many equal divisions as the
cipher disc, to contain the letters, figures, or other marks to be put into cipher.
These letters et cetera constitute the "ordinary code." When the cipher code
occupies an aliquot part of the margin of the cipher disc, the ordinary code takes
up the same aliquot part of the ring, and for convenience this should be the upper
half of the ring, a similar aliquot part in the lower half being filled in with a
separate set of letters, figures or marks. In such a case the last-mentioned set of
letters et cetera constitutes a separate "key code." Each mark space of the key
code, or of the ordinary code when there is not a separate key code, is perforated
for the purpose of inserting a small stop when the apparatus is to be used.
The apparatus is used as follows:-Choice having been made of a key word or
combination, a stop is inserted in the perforation in each mark space corresponding
to the several letters or marks in the word or combination; for example, supposing
the key to be "Thursday January 2," containing the different letters or figures a, d,
e, j, n, r, t, u, y, 2, a stop would be inserted in the spaces corresponding to each of
these. On rotating the cipher disc, the pointer above mentioned comes in contact
with the first stop, and the mark in the cipher code corresponding to the adjacent
letter or mark in the ordinary code which is to be put into cipher is then read off.
The pointer being released is carried by the rotation to the other stops in succession.
When all the stops have been passed, the pointer, by the continued rotation in the
same or the reverse direction, is again brought in contact with them in the same or
the reverse order, as may be preferred. Thus, the key stops having been once set,
any amount of matter may be put into cipher with great rapidity. The work of
deciphering is equally rapid; the reading off is of course from the cipher code to
the ordinary code.
The choice of a key being unlimited, its discovery, and the consequent
unravelment of a writing in cipher, is practically an impossibility.
Dated this 2nd day of January 1894.

page_text: COMPLETE SPECIFICATION.
An Improved Apparatus for Use in Cryptographic Writing.
JAMES WILLIAM NOBLE Electrical Engineer 26 Pepys Road South New
Cross Londou S.E. 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 consists of an apparatus for cryptographic purposes, having the
following advantages, namely. (1) Compactness. (2) Simplicity of construction
and working. (3) Rapidity of transcription into or out of cipher. 4 The key
may consist of any word or words or arbitrary combination of letters or figures.
5 Impossibility of deciphering by persons not possessed of the key. 6 Terminating
syllables of words, or suffixes, may be put into single cipher.
The apparatus of which Fig. 1 is a plan, consists of,
(1) A circular disc a a which can be rotated in either direction by any ordinary
method. I prefer however to use for this purpose a milled head h h at the back of
the apparatus and affixed to the central axis c; when the milled head is turned in
either direction the disc rotates in the same direction.
I call a a the cipher disc; its margin is divided into a number of equal spaces
which contain, the letters, figures, or other marks constituting the cipher code.
Thus the cipher code may consist of the ordinary alphabetic characters only, or
these may be combined with figures; and the number of spaces into which the
margin of the cipher disc is divided will be equal to the total number of such
marks employed, I prefer however that the cipher code should consist only of the
twenty six letters of the alphabet, as shown in the fig., and these may be arranged
in any order, though it will be found convenient for the purpose of deciphering, to
arrange the letters in their usual order. The cipher disc has a small rod or
pointer d affixed to it, so that as the disc rotates the pointer also rotates with it.
It is convenient to fix this pointer so that its end is always directed towards the
letter A. The end of the pointer extends beyond the circumference of the cipher
disc as shown in the fig. This end is made of a springy piece of thin steel or other
suitable substance, and may be straight as at e, or of the form shown at f. I call
this pointer the indicator; it is an important feature of the invention, and its use
will be hereafter explained.
(2) An exterior fixed ring 9 g whose inner circumference coincides with the
circumference of the cipher disc. This ring has as many equal divisions as the
cipher disc, to contain the letters or other marks which are to be put into cipher.
These letters or marks constitute the "ordinary code." In Fig. 1 the number of
mark spaces is twenty-six to coincide with the twenty-six spaces on the cipher disc,
but figures or other marks might be added to both the cipher code and the ordinary
code. I prefer however to insert figures and word endings in a second ring of mark
spaces outside the ring gg. Each one of the spaces in the ring g g is perforated to
receive a small stop, either a plain cylindrical rod, or notched as at s, the purpose
of which is to indicate by a click when the end of the indicator is passing over the
particular mark space in which it is inserted. The stops are placed only in the
spaces whose marks form a portion of the key.
The mode of using the apparatus is as follows:-The cipher disc is rotated till
the indicator, which always points to A in the cipher code, also points to A in the 4
ordinary code. Choice having been made of a key word or combination, a stop is
inserted in each mark space corresponding to the several letters or marks in the
key. Thus supposing the key to be "Thursday January 2," containing the
different marks a, d, e, j, n, r, t, u, y, 2, a stop is placed in each space in the ordinary
code containing these marks. Suppose the matter to be put into cipher is "send 5
it quickly." On rotating the disc continuously to the right, the spring end of the

page_text: indicator comes in turn in contact with the stops inserted in the mark spaces; at
each successive contact a click is heard, and the operator looks at the letter or
mark which he is putting into cipher, and notes the letter adjacent to it in the
cipher disc, which is then written down as part of the cipher matter. Thus the
message "send it quickly "would, when using the arrangement shown in Fig. 1,
be rendered as sbfu vc xuklkb, the last letter b being the cipher for the suffix ly.
To decipher, the stops are to remain in the same mark spaces, and the disc is
rotated. At the first click, the letter in the ordinary code adjacent to s in the
cipher code, is found to be s, at the next click the letter adjacent to b in the cipher
code is found to be e, and so on till the whole is deciphered.
It will be seen that the ciphering and deciphering are very rapidly executed, as
the only movement is the rotation of the cipher disc, which will be as rapid as the
operator's skill will allow of.
As in the form of apparatus shown in Fig. 1, one-half of the letters or marks are
always inverted with respect to the operator, I prefer the modification shown in
Fig. 2, in which the cipher code occupies an aliquot part only (one-third is a
convenient part) of the cipher disc margin, and is repeated as shown in the fig. ;
the ordinary code also takes up the same aliquot part of the ring, and for convenience
this should be in the upper part of the ring; a similar aliquot part in the lower
part of the ring is filled in with a separate set of letters, but preferably in the
reverse order, constituting a separate "key code." The stops are placed in the
mark spaces of this key code, and the end of the indicator comes successively into
contact with them. When all the stops have been passed, the direction of rotation
is reversed; so that the motion of the cipher disc is, in this modification, alternately
right and left. This adds, if possible, to the difficulty of deciphering without a
knowledge of the key.
This change in the direction of the motion of the cipher disc I prefer to effect
by affixing the disc to a wheel w running on a fixed axis, and actuating this by
turning a second wheel u by the left hand, a string, or its equivalent, passing over
both pulleys or wheels.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is
1. The use of an indicator in conjunction with stops for expediting and extending
cryptographic writing, and rendering its decipherment impossible without a
knowledge of the key.
2. The construction of cryptographic apparatus containing an indicator and
stops, substantially as shown in Figs. 1 and 2.
Dated this 4th day of October 1894.
JAMES WILLIAM NOBLE.