Page 252 - The Secret War in the Italian front in WWI (1915-1918)

THE SECRET WAR ON THE ITALIAN FRONT IN WWI (1915 – 1918)

The distribution of the Coding
and Decoding Tables to mobilised
units only took place between the
end of August and the first days
of September. This delay is a clear
sign of the resistance made by
the Encoding Sections vis-à-vis a
modest complication in the ciphering
process .
65
Each table fitted on a sheet of paper
that, once folded into fourths, became
of pocket size, showing in all evidence
the instructions printed on the back of
the tables (picture 11.11) .
66
In the ciphering table (picture
11.12a), for each pair of columns,
the numbers read at the bottom of
the pages of Red Book were on the
left and in boldface. On the right,
the three or more groups of numbers
between 000 and 999 arranged in
a disordered way are intended for
replacing the one on the left. The code
groups had to be chosen carefully to
avoid repetitions, especially within
the same cryptogram.
11.11 Instructions for the use of encoding and decoding tables
for the Red code The last two columns to the right of
the table provided the match between
the original figures next to the words
on each page of the Red Code and the corresponding disordered replacement groups .
67
In the decoding table (picture 11.12b), one could see in boldface the groups from 000 to 999
inserted in the cryptograms and, next each of them, the corresponding page numbers of the
Red Code. The last columns on the right allow to decode the digits that matched to the words
contained on each page.
At the same time as the tables were adopted, the Special Code - now, the Red Code protected
by the tables - was not more used by Brigade Headquarters or below, with the purpose of
limiting the dissemination of tables and the amount of cryptographic material that the enemy
could intercept.
The adoption of the tables in the summer of 1917 seems to have blocked the decryption of
dispatches since Ronge never mentions them in his memoirs, while Figl briefly states “the
daily change of page numbers”, showing he did not understand the new technique the Italians

65 The date the encoding and decoding tables were adopted appears in the confidential letter of the Ministry of War of 23
August 1917, AUSSME, Series F3, env.373. The tables had been circulating since July for final approval, as per the logs of
Section U.
66 AUSSME, Series F3, env.28.
67 The possibility of encoding a page number with multiple groups depends on the ratio of about 1:4 between the number of
pages of the Red code and the number of groups between 000 and 999, all of which were used in the tables.

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