Page 209 - The Secret War in the Italian front in WWI (1915-1918)

CHAPTER TEN

To get a general idea of the variety of topics covered by the Cryptographic Unit, the meeting on 24
November 1916 between Sacco and the Chief of Censorship Unit of the Italian Post and Telegraph
Ministry regarding “the supervision of telegrams by prisoners of war” may be recalled. In fact,
some Italian officers who were prisoners in Austria had sent their families telegrams - forwarded
by the Red Cross - which conveyed, by means of concealed languages, military information they
had learned by chance or on purpose. There was an evident concern that Austrian prisoners might
be doing the same.
This book only investigates the activities of the Unit concerning military cryptography and does
not delve into other aspects of the multifaceted work carried out by Sacco and his colleagues during
WWI . In particular, this chapter illustrates some cedes and chiphers used by the Armed Forces
12
of Central Empires and by their Allies and presumably broken by or known to the Cryptographic
Unit between late 1916 and 1917.

10.2 ITALIAN ANALYSTS’ SUCCESSES

The naval codes
The logs of Section R dated 11 November 1916 mention the “transmission to the Royal Navy
General Headquarters, Venice, of the key 39842 of the Austrian Navy Code and of some r.t.g.
(radio telegrams, A/N) decrypted with that key” .
13
Since the Austrian Navy Code is most likely the same placed at the top of the list composed by
Sacco in August 1916 and described in some pages of his booklet full of precise data regarding
also another code of the German navy, an interesting question arises regarding the circumstances
under which Sacco and his colleagues got them.
It is known that before the summer of 1916, the Italian navy had exploited some opportunities to
explore the hulls of sunken Austrian ships. For instance, immediately after the battle of Cattaro, on
28 December 1915, the sunk destroyer Lika had been inspected by Italian deep-sea divers tasked
to recover interesting documents and above all ciphers.
Moreover, in April 1916, the Italian navy had recovered the Austrian submarine minelayer U24 -
built in Germany and staffed with German personnel - which had sunk the previous month, due to
the explosion of one of its mines, and had been lying in shallow waters in the Gulf of Taranto. Like
all vessels of that kind, the submarine was equipped with radio trans-receiver and with both the
code of the Austrian Navy and the HVB of the German Navy. The two code books were probably
recovered on that occasion, and the submarine, still in fairly good shape, after refurbishing joined
the Italian navy with the name X1.
The presumed date of the capture suggests that the edition of the Austrian code held by the
Cryptographic Unit was the first of a series adopted by the Austrians navy during the war and
identified with the initial acronym KOD. In fact, according to research carried out in the English
archives, the next version called KODEIN was issued in September 1916, therefore after the U24

12 For diplomatic telegrams, see: C. Colavito, l Cifrari Diplomatici e il Reparto Crittografico dell’Esercito Italiano nella
Grande Guerra, GNOSIS, Rivista Italiana di Intelligence, 1/2019.
13 Section R logs, 11 November 1916, AUSSME, Series B1, 101S, Vol. 251c.

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