The sample of a cipher in a novel* is unworkable but the idea has possibilities. I used that idea to create a short cryptogram.
(1)
Each letter of the plaintext is substituted by 4 digits, as explained below in (4).
S E N D M O R E M O N E Y
7849 7560 6488 8369 4568 2651 4977 6146 6542 5530 6743 6752 4479
(2)
Re-format for transposition
78 49 75 60 64 88 83 69
45 68 26 51 49 77 61 46
65 42 55 30 67 43 67 52
44 79 00 00 00 00 00 00
Columnar transposition (there was no added transposition in the book)
G O L D F I S H
3..7..6..1..2..5..8..4
-----------------------
78 49 75 60 64 88 83 69
45 68 26 51 49 77 61 46
65 42 55 30 67 43 67 52
44 79 00 00 00 00 00 00
Write columns 1-8 to a line
60 51 30 00 64 49 67 00 78 45 65 44 69 46 52 00 88 77 43 00 75 26 55 00 49 68 42 79 83 61 67 00
(3) Reformat for transmission (add one more 0 to fill out the last group)
60513 00064 49670 07845 65446 94652 00887 74300 75265 50049 68427 98361 67000
(4) How it works. The difference (positive or negative) between the pairs in each 4-digit block
maps to a numerical substitute of a plaintext character.
The numbers can be created ad hoc or selected from a spreadsheet.
Excel method:
Char Sub First Number Second Number
1 1 RANDBETWEEN(11,99) (First Number-Substitute)
2 2 RANDBETWEEN(12,99) (First Number-Substitute)
3 3 RANDBETWEEN(13,99) (First Number-Substitute)
4 4 RANDBETWEEN(14,99) (First Number-Substitute)
5 5 RANDBETWEEN(15,99) (First Number-Substitute)
6 6 RANDBETWEEN(16,99) (First Number-Substitute)
7 7 RANDBETWEEN(17,99) (First Number-Substitute)
8 8 RANDBETWEEN(18,99) (First Number-Substitute)
9 9 RANDBETWEEN(19,99) (First Number-Substitute)
0 10 RANDBETWEEN(20,99) (First Number-Substitute)
A 11 RANDBETWEEN(21,99) (First Number-Substitute)
B 12 RANDBETWEEN(22,99) (First Number-Substitute)
C 13 RANDBETWEEN(23,99) (First Number-Substitute)
...
The second pair of numbers is the reverse of columns 3 & 4
Z can be substituted by any of 108 4-digit numbers.
9963, 9862, 9761, 9660, 9559, 9458, 9357, 9256, 9155,
9054, 8953, 8852, 8751, 8650, 8549, 8448, 8347, 8246,
8145, 8044, 7943, 7842, 7741, 7640, 7539, 7438, 7337,
7236, 7135, 7034, 6933, 6832, 6731, 6630, 6529, 6428,
6327, 6226, 6125, 6024, 5923, 5822, 5721, 5620, 5519,
5418, 5317, 5216, 5115, 5014, 4913, 4812, 4711, 4610
and the reverse pairs.
Y has one more substitute pair than X. X has one more substitute pair than Y, and so on.
This can be made more difficult but I only want to present it as something different.
*"The Cruise of the Esmeralda" by Harry Collingwood
