Page 306 - The Secret War in the Italian front in WWI (1915-1918)

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

Despite the limited traffic generated by Austrian stations, frequently updated summary maps of
the type shown in picture 13.12 were drawn since January 1918 . In the months that followed, the
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recognition of vast network “ranging from the east of Trento to the sea” was perfected. It included
four groups of stations respectively located in Trentino, in the area between Astico and Brenta,
in the area east of the Piave river, and at the east of Tagliamento. All stations had been identified,
together with their more frequent links, the frequencies used, etc .
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As already mentioned, at the end of May, at the starting for the Second Battle of the Piave river
preparations, Austrian radio traffic quite vividly resumed and the silent cryptographic struggle
between the opposing sides became tight again, hence showing that the Italian analysts’ knowledge
and skills had become comparable to those of the enemy.
In June 1918, as the Battle began, the Italians were well prepared even in Radiocommunication
Intelligence. Luigi Sacco had been at the front at least from 15 June and his contributions to
identify and pinpoint enemy radiotelegraphic stations in the early days of battle are testified by
a report he wrote from the war zone. As a preliminary information, he wrote that “the enemy
radiotelegraphic activities resumed on 28 May; until the morning of 15 June, radiogoniometry
research localised all the enemy stations between the Brenta and the Piave rivers, mainly in the
Feltre, Fronzaso, and Primolano area” .
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Sacco then described the development of the Austrian radio communications in the days
from 15 through 18 June. The map in picture 13.13 indicating the locations of four groups
of main stations, is attached to his report. The first group, belonging to the 11 Austro-
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Hungarian Army, was pinpointed in the region of Feltre; the second group deployed across
Conegliano, Vittorio, and Sacile, where the 6 Army operated; the third group located around
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Motta di Livenza was part of the 5 Army. The fourth group stationing in rear position east
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of the mid-Tagliamento, with three active stations, could coincide with General Boroevic’s
Headquarters.

The radIograMs of coneglIano veneTo
In addition to locating the Austrian stations, Sacco committed himself to decrypting the intercepted
dispatches. He described the main characteristics of the new code the Austrians had adopted on
the first day of the attack, saying it was a “two-part code made of a thousand three-digit groups”,
without any over encoding.
Given the resistance to cryptoanalysis of two-part books, the Austrian Headquarters likely believed
the time to break the new code, adopted on 15 June, could be larger than the expected duration of
battle started with ambitious goals to be achieved in a few days. However, they had not taken into
due account the galliard resistance of the Italian army, nor they had considered some cryptographic
faults, that is, the ‘laziness’ of a telegraph operator who, instead of searching in the dictionary
for code groups corresponding to entire words, encoded messages letter by letter. He felt more at
easy this procedure because the letters were grouped at the beginning of the code. To this respect,
Sacco wrote:

32 1 Radio Goniometric Section, Bollettino n°5, Servizio RT campale dell’Esercito austro - tedesco nel Veneto nel mese di
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gennaio 1918, (Austro-German field RT Service in the Veneto region in January 1918), ISCAG, Coll. 249.
33 3 Telegraphic Engineers Regiment, 1 Radio goniometric Section, Bollettino n°7, March 1918, ISCAG, Coll. 249.
rd
st
34 Intelligence Service, RT Unit, Riassunto sull’attività RT nemica (Summary of the enemy radio activity), signed by Luigi
Sacco, War Zone, 18 June 1918, ISCAG, Coll. 249.

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