Stories from the trenches : $b humorous and lively doings of our boys "over there"Case, Carleton B. (Carleton Britton)
History
Stories from the trenches : $b humorous and lively doings of our boys "over there"
Case, Carleton B. (Carleton Britton)
World War, 1914-1918 -- Anecdotes
As a starting-point the cipher-man assumed that the text was in English
because he got it out of an English newspaper, but he did not stop
there. He checked it from a negative view-point by finding the letter
_w_ in it, which does not occur in the Latin languages, and by finding
that the last fifteen words of the message had from two to four
letters each, which would have been impossible in German.
Then he proceeds to analyze. The message has 108 groups that are
presumably words, and there are 473 letters in it. This makes an
average of 4.4 letters to the group, whereas one versed in the art
normally expects about five. There are ninety vowels of the AEIOU group
and seventy-eight letters JKQXZ. Harking back to that first statement
of percentages, it is certain that this is a substitution cipher
because the percentage does not check with the transposition averages.
The canny man with the sharp pencil then looks for recurring groups and
similar groups in his message and he finds that they are:
AIIWG AII BKSM BKAI CT CTWY CTW DLMMJXL DL ESF ESBP FJNVX FJHVSI NPSI
NPUXQG OSB OSY ROSB OL OL PORTELOGJ PO SQ SQA TP TP TLBWTPZ TLFNS
TLFTWMC UVZUA UVD UV SMKUL XMKUHW YJL YJVTI.
Passing along by the elimination route he refers to his frequency
tables to see how often the same letters occur, and he finds that they
are all out of proportion, and he can proceed to hunt the key for
several alphabets.
He factors the recurring groups like a small boy doing a sum in
arithmetic when he wants to find out how many numbers multiplied by
each other will produce a larger one. The number of letters between
recurring groups and words is counted and dissected in this wise:
AII AII 45, which equals 3x3x5
BK BK 345, which equals 23x3x5
CT CT 403, no factors
CTW CTW 60, which equals 2x2x2x5
DL DL 75, which equals 3x5x5
ES ES 14, which equals 2x7
FJ FJ 187, no factors
NP NP 14, which equals 2x7
OL OL 120, which equals 2x2x2x3x5
OS OS 220, which equals 11x2x2x5
OSB OSB 465, which equals 31x3x5
PO PO 105, which equals 7x3x5
SQ SQ 250, which equals 2x5x5x5
TLF TLF 80, which equals 2x2x2x2x5
TP TP 405, which equals 3x3x3x3x5
UV UV 115, which equals 23x5
XMKU XMKU 120, which equals 2x2x2x3x5
UV UV 73, no factors
YJ YJ 85, which equals 17x5
Now the man who is doing the studying takes a squint at this result and
he sees that the dominant factor all through the case is the figure
5, so he is reasonably sure that five alphabets were used, and that
the key-word had, therefore, five letters, so he writes the message in
lines of five letters each and makes a frequency table for each one of
the five columns he has formed, and he gets the following result:
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account