Page 301 - The Secret War in the Italian front in WWI (1915-1918)

CHAPTER THIRTEEN

Unit became aware of this evolution, and in the last months of the conflict included this code
among those in service inside units above the Division .
18
In his memoirs, Ronge mentioned the D code only once, that is, when it was found on an Italian
Cavalry Officer captured on 9 July 1918, also mentioning in a note that the code had been adopted
shortly before, showing little knowledge not only about the time of code introduction, but also of
the possible similarity with the ‘syllables and words cipher’ that Ronge believed had been adopted
in June of the previous year .
19
However, besides acquiring the code booklet on that occasion, any Austrian attempt for decrypting
dispatches encoded with the D was unsuccessful, apart from eventual messages coded with the
edition found on the captured Italian Officer and only before it was radically modified under its
instructions for use.

The r code
In April 1918, the R (Regimental) code was distributed to the Headquarters of the Infantry Regiments
and equivalent units of other combat Arms. It was meant to provide a handy cipher protecting the
secrecy of phonograms, but also of radiograms exchanged between smaller combat units.
Picture 13.9 shows the cover of the
15-page user’s manual preserved
in the Archives together with two
copies of the code - one partially
filled, and one empty - contained in
a sheet that, when folded into four
parts, became of pocket size .
20
As for the D code, the basic feature of
R is the drawing of the code groups.
The specimen in picture 13.10, filled
by a fighting unit is useful to briefly
explain its characteristics. A single
sheet contains four coding tables
identified with letters from a through
d . This last table is also used in
21
13.9 Cover of the Instruction Manual for the "R code" (ISCAG combination with table e like the
Library) auxiliary tables of the service ciphers.
The other three tables f, g and e were
used for decoding purposes .
22

18 Intelligence Service, Norme per l’uso e la compilazione di cifrari, op. cit.
19 M. Ronge, Der Radiohorch, op cit., p. 35 - 36. Immediately after that, Ronge reported about a dispatch from the Italian 16
th
Corps that reads, “the enemy has the D code”. Ronge adds that, as a countermeasure, they ordered “the replacement of digits
from 0 to 9 with other random digits”. This hypothetical over-encryption method did not match the instructions of the code.
20 Library of the ISCAG, coll. XXXI A, n°11129.
21 AUSSME, Series B4, env. 521. There were about 100 plaintext words in total, of which 70 in table a, and 30 left to the
discretion of regimental Headquarters in table b; 30 individual letters, endings, and numbers in table c. These were all encoded
through three-digit code groups. There were also 80 syllables with two-digit code groups (Table d). The 3-digit numbers
ended in 0 or 1.
22 For the groups ending with figures other than 0 and 1, table f should be used in combination with table e.

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