Page 188 - The Secret War in the Italian front in WWI (1915-1918)

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

and would have been more resilient to decryption had it comprised an adequate number of null
items and homophones which, however, seem to be missing in this case.
During the following March, the Austro-Hungarians conveyed some misleading radio messages
- what is nowadays termed deception - by having Captain Figl prepared a cipher, easy - but not
too easy - to break, applied to the dispatches. Those transmissions were concerning the fake
ongoing preparation of a simultaneous attack on the Trentino and on the Isonzo front, while the
Austro-Hungarian Command’s real intention was to launch an attack only in Trentino. This really
happened with the famous Strafexpedition, although with considerable delay compared to the date
originally set.
Undoubtedly, the Italians could decrypt some radiograms transmitted on that occasion by the
Austro-Hungarian radio stations. For instance, in mid-March 1916, the War Situation and
Operations Office reported a radio interception about the delivery by train of ten bridge segments
heading for the Tolmino area, in view of an Austro-Hungarian attack in that sector of the Isonzo
front. O. Marchetti declared that the attempt on the Austrian part had failed as, in early April, the
Intelligence Office stated that “the attack will be in Trentino on the plateaus and in Val Sugana
[…], suspecting that some poorly coded dispatches are false as spread by enemy radio stations
with the intention to deceive us” .
15
In sum, the electronic warfare on the Italian front had begun!

9.2 AN INCREASE IN AWARENESS

an alerT froM The suPreMe coMMand
On an unspecified day in March, an Austrian listening radio station that had moved too close to
the front line was captured by the Italians. The documentation and material seized along with the
station are unknown, yet the countermeasures adopted by the Austrian Intelligence Service were
so radical as to let one infer that the information fallen into Italian hands was not negligible .
16
The information achieved by the Italian Intelligence on that occasion probably led to the awareness
of the Austrians possession at least of some Italian codes and ciphers. As a matter of fact, on 29
March the Operations Division of the Supreme Command informed all Armies’ Headquarters and
the other concerned branches of suspecting that parts of the Red Code could be held by the enemy,
and peremptorily prohibited to use it for any radiotelegraphic communications .
17
The Intelligence Office reiterated the prohibition in a letter sent in the following month to all
Commands which, going to some extent into cryptographic issues, reads:

the Red Code usage implies some risks even despite the changes to it (modified page numbering,
A/N), since the positioning and the progressive numbering on each page of the single items
remain unmodified, which is enough for a skilful cryptologist to identify the changes easily,
provided the large quantity of material available.
Furthermore, the extensive use of the Red Code naturally compromises its secrecy .
18

15 O. Marchetti, Il Servizio Informazioni, op. cit., p.115.
16 M. Ronge, Der Radiohorch, op cit., p. 6.
17 Supreme Headquarters, Operations Division, Service communication n° 6462 of 29 March 1915. AUSSME, Series F1,
env.108.
18 Intelligence Office, Letter, Ref. no. 8983, 29 April 1916, AUSSME, Series F3, env.50.

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