Page 248 - The Secret War in the Italian front in WWI (1915-1918)

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

Even more categorical are Sacco’s words as he added, “well known to the Cryptographic Unit, the
weakness of Italian ciphers was not appreciated by the Supreme Command and gave Gen. Ronge
the opportunity to boast the primacy of the Austrian crypto-analysis service” .
49
The obstacles and delays to change emerge from the cold chronicles of diaries and correspondence
which, on the other hand, unveil that innovation of the codes used by the Italian army began,
thanks to Sacco and his staff, in the early months of 1917, that is, well before the beginning of
1918, as is generally believed. The Cryptographic Unit, still undersized and overburdened, was
also tasked with the design of some new cryptographic systems for the Army, responding to the
efficient Austrian cryptologic machine. The general principle that only cryptanalysts can judge the
security of a cryptographic system was gaining ground during the war, even in the Italian army.
In January 1917, an entry about this activity appears in the logs of Sections R and U of the
Intelligence Service for the first time, just as Section U was asked to provide a list of terms for
the SI Code. The following notes in the logs leave no doubt about the meaning of acronym SI,
standing for Servizio Informazioni (Intelligence Service), namely the service for which the code
was exclusively designed, at least at the beginning. In Section R logs of March there are references
to the “drafting of the code for the Intelligence Service”, to the “Rules to preserve secrecy”, and
to the “Drafting the preface”, all referring to the SI code, which came officially into force on 1
May 1917 .
50
The Supreme Command, the various branches of the Intelligence Service as well as the Military
Attachés in the Italian embassies abroad were included in the initial SI distribution list, progressively
expanded to the Military Attachés at the Allied Headquarters in war zones, the Intelligence Centres
located in neutral countries, the Command of the Aegean Occupation Corps, etc .
51
The two-part SI code - a book of about 400 pages with more than 20,000 words - adopts code
groups of five digits chosen randomly. In addition to the dictionary, the code included lists of
locations, Services’ Headquarters, time measurements, etc.
The Cryptographic Unit managed the SI by frequently replacing or adding groups to adapt it to
the changing needs of its users. The first ‘amendments’ shown in picture 11.10 demonstrate the
experimental use of the code since March 1917 .
52
In his memoirs, Figl mentioned the SI code for the first time when he describes the analysis of
some radio dispatches sent by the Italian Liaison Officer within the French HQ in Coryza (Corça
in Albanian), in the autumn of 1917, that is more than six months after the dispatches encrypted
with this code were sent across extensive areas such as Albania, Cyprus, Aegean, Northern Europe,
etc. The Austrian Officer recognised, however, the difficulties he faced on this occasion and the
impossibility of penetrating the code that the Italians continued to employ, in total safety, until
almost November of 1917 .
53

49 L. Sacco, Manuale, op. cit, p. 309.
50 Section R Logs, 8 e 22 marzo 1917, AUSSME, Series B1, 101S, Vol. 267c; Diari Sezione U, op. cit., 13 e 23 aprile 1917,
AUSSME, Series B1, 101 D, Vol. 349d. The not-so-short time taken to create the ‘SI’ depended on its volume and the accuracy
required to make it consistent with the type of communications it was designed for.
51 ibidem.
52 AUSSME, Series H, Env.11.
53 O. Horak, Oberst a. D. Andreas Figl, op. cit., p.195 - 196. Andreas Figl said he had interpreted a hundred terms in the code
on this occasion but that his results had not improved because the messages had become rare and short.

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