In October
1940 Italian forces invaded Greece, in the area of Epirus, and
the Greek-Italian
war started. The Greek forces were able to contain the assault and the
Greek counterattack forced the Italians back into Albanian territory. After the
defeat of a major Italian offensive
in spring 1941 the front stabilized inside Albania.
German
forces invaded
Greece in April 1941 and made rapid progress due to the fact that
almost the entire Greek Army was fighting in the Epirus area. The remaining
units and the small British forces transferred to Greece in March-April 1941
were unable to stop them.
Then in May 1941 the Germans were also able to defeat
the Greek and British forces that had retreated to the strategic island of Crete.
What role did
signals intelligence and codebreaking play during that short conflict? Let’s
have a look at the limited information available:
The
Italian effort
Italy had two
codebreaking departments, one under Army and the other under Navy control.
The Italian
army’s intelligence agency SIM (Servizio Informazioni Militari) had a
cryptanalytic department that attacked foreign crypto-systems. This section was
headed by General Vittorio Gamba and was located in Rome. Personnel strength
was roughly 50 people (half cryptanalysts-half linguists and clerks).
The naval
intelligence agency SIS (Servizio informazioni Speciali della Royal Marina) was
divided into 4 branches. Branch B (Beta) was tasked with signals intelligence.
It was subdivided into cryptanalysis, interception and direction finding,
security and clandestine radio intercepts. The cryptanalytic department was
located in Rome and headed by Commander Mario De Monte.
Regarding the
Greek Air force communications, it seems that the cipher system used was simple
transposition (1). Considering the limited security of this system it is
reasonable to assume that it was solved by the Italian codebreakers.
The Greek
effort
At this time
there is almost no information available on the Greek Army’s cryptologic and
cryptanalytic effort during WWII. A report from 1938 (2) mentions the Greek Army
codebooks: small unit code 1937, large unit code 1937, small unit code 1938,
mobilization code 1937, cryptographic lexicon 1935.
Regarding
cryptanalysis it seems that the Greek Army Signal Corps may have been able to
exploit Italian communications (3). According to an article on Greek military
intelligence this information comes from British liaison signal officers:
‘In addition, according to British liaison
signals officers, Greek Signals Corps managed to decipher some Italian traffic
during the November/December battles in Albania. On 6 December, a British
lieutenant-colonel informed his superiors: “Herewith a batch of Italian traffic
intercepted by the Greek General Staff. Also, one copy of cipher ‘O.M.’ for
internal use of the Italian Army in Albania.” On 8 December, the reply
confirmed Greek success: “Many thanks to Greeks for citrario O.M. Tell them I
do not remember having seen it but I am very grateful for it and for any
further documents of this nature which may be of assistance in reading Italian
codes in Albania which I am afraid are not readable.” We could imagine that
Greek Signals Corps may have deciphered key traffic during October, prior to
the invasion. Unfortunately, at the Army History Service no files of Greek
signals operations can be found. Perhaps some material might be held at the
Military Archives Service but we must bear in mind that the 1941 German
invasion and the 1941-1944 occupation caused the destruction of many files of
sensitive army archives. As to Metaxas, he did not make any reference to
signals intelligence in his diary’.
The German
effort
The German
Army’s signal intelligence agency solved Greek Army and Air force ciphers.
According to the TICOM report I-170 in spring 1941 Greek AF single
transposition messages were solved and translated (4):
My first
employment was on the breaking and translating of Greek Air Force messages in
Spring 1941. The unit was in BUCHAREST at that time and later it was at BANJA
KOSTENIC in Bulgaria. C.O. was Hptm. SCHMIDT, head of the cryptography and
translation department from then until Autumn 1944 was Prof. Alfred
KNESCHKE, a Professor of Mathematics from Saxony.
The Greek
Air Force messages were a matter of simple boxes, the text being sent in T/L
groups. The indicator took the form of 3 letters which were always in a given
position, the first three T/L groups and had to be knocked out before entering
the cipher text in the clear box. This was broken by writing out the cipher
text in vertical strips of varying depth and sliding them against each other
until a few Greek syllables appeared above one another. After the initial break
it became clear that a large part of the messages began with the words
‘parakalw', 'anaferw’ and ‘apesteilamen’ and that the width of the box was as a
rule between 15 and 22 columns. On the basis of the above, initial words, all
messages were tried out on the normal number of columns and nearly everything
was read. I had less to do with the actual evaluation, firstly because the two
departments were kept separate and secondly because we were kept fully occupied
with our own job. In any case the content of the messages was usually of
insignificant strategic value, although the continuous check on officer
personalities, deliveries of stores and knowledge of airfields combined with
D/F bearings indirectly contributed to considerable tactical results'.
Regarding
Greek Army ciphers there is some information available from the postwar
interrogations of Army cryptanalyst dr Buggisch. According to
TICOM report I-58, in early 1941 he investigated a Greek codebook enciphered
with a 35 figure repeating additive sequence (5). Progress was made in the
solution of the cipher but the campaign ended just as the system was starting
to be exploited operationally:
c. Greek -
In early 1941, B. solved a 5-letter code with a 7-cyclic recipherment (period
of 35). Just getting to operational speed when the campaign ended.
German
exploitation of Italian communications
It seems that
the codebreakers of the German Army did not only monitor the communications of
their enemies but also solved the codes and ciphers of their Italian allies.
The War Diary
of Inspectorate 7/VI shows that Italian codes and ciphers were worked on by
Referat 4 (6). According to the reports of Referat 4 for early 1941, 5-figure and
3-figure codes were worked on:
The 3-figure Army
code was successfully solved and read. A 5-figure Air Force code was also
worked on and the encipherment solved. A 5-figure enciphered code used by the
higher command in Albania was worked on and code groups recovered.
The reports
say that emphasis was put on the analysis of the systems used by the higher
echelons of command.
Some
interesting statements regarding Italian radio communications are made in ‘War
Secrets in the Ether’ - vol 3, p25 written by Wilhelm
Flicke (he was in charge of the OKW/Chi’s Lauf intercept station):
‘Mussolini
had decided on war in the Balkans. Von Papen's warnings made Hitler averse to
any immediate action there, but he was only able to restrain Mussolini to the
extent of limiting Italy to war with Greece. In less than two months the
Italians, who had the advantage in everything save morale, were badly beaten.
The political leaders were terribly surprised and the Chief of General Staff,
Marshal Badoglio, and numerous other high officers were relieved of their
duties. This did not help matters.
One of the
most decisive factors during those weeks was the manner in which the Italians
employed radio. The set-up was the same as that used in maneuvers of previous
years. They employed open circular traffic; that is, they used one uniform
frequency for a group of stations belonging to the same unit (e.g., the
stations of three infantry regiments of a division for traffic with one another
and with the divisional station) and each station used only one call sign for
all its traffic. The call sign was supposed to change daily but was often used
for several days; not infrequently a change in call sign was followed by errors
which betrayed the change. Traffic was so heavy that the enemy always had a
chance to take bearings and fix locations. Frequently messages were sent in
clear. Several units of the Italian Eleventh Army distinguished themselves in
this respect. Moreover, the Greeks had obtained at least two Italian
army cryptographic systems, how I do not know, but it is certain that in the
very first days of the campaign they could decipher a large part of the Italian
messages. This enabled them to learn promptly most of the dispositions of the
Italian command and to take appropriate action. The superiority thus gained
was utilized cleverly and a series of military actions took place which
heretofore would never have been deemed possible’.
Notes:
(2). German
Foreign Ministry’s Political archive - TICOM collection - file Nr. 3.676 - Griechenland 1940 - Korresp. betr. Neue
milit. Schlüssel u. Vernichtung alter.
(6). Kriegstagebuch
Inspectorate 7/VI - German Foreign Ministry’s Political Archive - TICOM
collection – files Nr 2.755-2.757
Acknowledgments: I have to thank Enrico
Cernuschi for sharing the messages from the Archivio dell' Ufficio Storico
della Marina Militare.
