Page 318 - The Secret War in the Italian front in WWI (1915-1918)

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

All the S family adopted three-letter code groups taken from a 13-letter Italian reduced alphabet,
giving rise to 1.716 possible code groups . In picture 14.1 where one page of coding and decoding
2
parts is shown, in addition to the random choice of the code groups, the plenty of homophones can
be noticed for letters such as “a” and common terms such as “artiller - y - ies”.
With the purpose of modifying the three-letter groups obtained from the dictionary, all the S codes,
applied over-encoding with a key designated at the beginning of each dispatch by a three-letter
‘indicator’. Each key led to a position in the ‘table of keys’ where the replacements to be made for
each letter of the groups resulting from the first encoding were shown . The encoding telegraphists
3
chose the key at their own discretion and therefore over-encoding could vary from a dispatch to
another. In cryptograms, pairs of code groups created sets of six letters.
The introduction of the S system triggered a relevant issue for the Austro-Hungarian analysts, so
much so that, in referring to the great efforts made to incept the break of SB, Figl wrote: “with
daily indicators, the enemy was much better protected against us than in all previous ciphers. Our
good fortune was that he only had all the worthy ideas towards the end of the war. If the enemy
had started the war with these lists of conventional names, with the list of indicators and with the
CSB, who knows...” .
4
Figl attempted to break the code by steps and faced considerable difficulty. It took him about ten
days after the beginning of September to create a list of over-encoding indicators, that is, more
than a month after the code was used for the first time . Of course, finding those indicators does not
5
imply he was able to identify the tables and the approximately 1,700 items of the two-part code.
To the success of the Austro-Hungarian Chief analyst largely contributed recurrent ‘non-compliance’
of the Italian operators with the regulations, as for instance the infrequent replacement of keys.
In fact, the circular letter for the distribution of the SA, entered service on 20 October, explicitly
ordered the operators to “observe the fundamental rule of using all indicator groups of the table
(of keys), and not just one or two, as many do. This would remove all the advantages of double
encoding without diminishing the burden of entailed work” .
6
The partial breaking of the SB, as Figl himself acknowledged, remained the last success of the
Penkalas. However, it was not exploited for long, as the Italians replaced it with new Series S
codes - namely SA and SC - and adopted the T1 service cipher, hence frustrating all enemy efforts.
These new codes and cipher were never quoted by Austrian sources, except for the SA which Ronge
claimes he discovered on 27 October because an Italian radio telegram started declaring to use SA
with over coding, but he does not state any decrypting of the following part of the cryptogram .
7
The SC code was also available before the end of the conflict, as for a circular letter dated 23
October, where the indicator groups to be used in the mixed-use of the S ciphers, are listed .
8
The last delivery in the Series S, the SD code, occurred after the armistice.

2 13x12x11 = 1,716.
3 Even the table of keys contained an encoding and a decoding part since substitutions of the 13-letter occurred in a completely
random manner.
4 O.J. Horak, Oberst a.D. Andreas Figl, op. cit., p. 221 - 224; CSB stands for Code SB. Unlike Figl reported, there were no
‘daily indicators’, but rather changing from message to message (M. Ronge, Der Radiohorch, op. cit., p. 38).
5 O.J. Horak, Oberst a.D. Andreas Figl, op. cit., p. 221 - 224.
6 Chief Inspector, STM, Circolare riservatissima del 13 ottobre 1918, ISCAG, Coll. 229.
7 M. Ronge, Der Radiohorch, op cit., p. 41. Ronge writes about a cipher called C-S-A in service since 1 August 1918 for the
st
Italian Air Force, forced on 26 September (M. Ronge, Der Radiohorch, op cit., p. 47). On the contrary, the enter service of
SA for all radio stations starts from 20 October. The two ciphers do not match.
8 Chief Inspector, STM, Circolare riservatissima del 23 ottobre 1918 (Very confidential circular of 23 October 1918), ISCAG,
Coll. 226.

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