Page 212 - The Secret War in the Italian front in WWI (1915-1918)

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

obtained in identifying the new key of the Austro-Hungarian navy cipher” . However, the meeting
18
showed Pellerani’s efforts had failed to achieve significant results, therefore the Unit continued to
help the Navy in finding the following keys .
19
Every two weeks - the interval of time between subsequent key changes according to Sacco - the
Cryptographic Unit would usually complete the process of reconstructing the new key in a few
hours . In addition, regarding the Austrian navy code, Sacco’s Manual reads: “the over-encoding
20
keys changed every two weeks at the latest”.
It also adds that “the encoding tables (of the paragraph 59 type) would be reconstructed after a few
days” . Since the paragraph 59 of the Manual is dealing with “over-encoding with pronounceable
21
words”, it comes out that dispatches ciphered with the Navy Code were also decrypted when the
Austro-Hungarian navy adopted code words of ten letters making up pronounceable words. This
operation resulted to be more difficult as it required the rebuilding of tables variable over time and
including two-part encoding lists of one hundred terms: yet it would be carried out in a few days .
22
Austrian surface vessels, especially during the last phase of the war adopted one of the following
editions of the code and applied more complex over-encoding methods and variable conversion
tables that changed daily. This made decryption of dispatches more difficult and considerably
engaged also the English and French cryptographic services . According to Kahn, some analysts
23
of ‘Room 40’ at the British Admiralty were sent to Italy in the autumn of 1917 to work with the
Italian navy to solve the most complex over-encoding methods .
24
Sacco’s notebook also includes a description of the German Navy’s code called HVB -
Handelsverkehrs Buch (commercial book) used by merchant ships as well as by submarines and
Zeppelin airships until early 1916 . The code words are, in this case, made up of four letters
25
selected from a 19-letter alphabet and arranged in alphabetical order. Seemingly, the acquisition of
HVB did not bring about great advantages because the code was already “compromised”, leading
to its replacement by the German Navy .
26
Conversely, the availability of KOD impacted the decryption of naval and submarine Austro-
Hungarian communications, generating a cryptologic situation that was, at least for some time,
roughly the reverse to that concerning the Red Code on the land front.

InforMaTIon froM The MIddle easT
On 10 November 1916 and on the 14 and 16 of the same months, the logs of Section R reported
th
th
news regarding the decryption of radiograms exchanged between Berlin and Constantinople,
between Vienna and Constantinople and between Izmir and Aydin. One of the adopted ciphers
was called German-Turkish RT or sometimes R2.

18 Section R logs, 2 December 1916, AUSSME, Series B1, 101S, Vol. 251c
19 Collaboration continued over the following months, when Sacco frequently met Lieutenant Maltese, Chief of the
Radiotelegraphic and Cryptographic Branch of Italian Navy.
20 L. Sacco, Manuale, p.309.
21 ibidem.
22 L. Sacco, Manuale, p.119 -120. For clarifications regarding the methods to identify an over-encoding key, in case of known
code, see pp. 235 - 237 of the Manual.
23 N. Sifferlinger, op. cit., p.164.
24 D. Kahn, op. cit., p. 278.
25 Alberto Santoni, Il Primo Ultrasecret, l’influenza delle decrittazioni britanniche sulle operazioni navali della guerra 1914
-1918, Mursia, 1985, p. 58 - 60.
26 ibidem.

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