Page 150 - The Secret War in the Italian front in WWI (1915-1918)

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

capitals, etc.), for a total number
of pages amounting to 252. Many
positions are empty and allow
new items or ‘nulls’, as groups
with no meaning, to be included
into dispatches .
43
According to a procedure
commonly adopted for increasing
the secrecy of paged codes, the
page numbering used in coding
and decoding could differ
from the strictly progressive
numbering shown at the bottom
of each page. In the first page of
the dictionary (picture 7.10) the
page numbers written manually
and erased at the top of the page
lead to infer that, during the
service period of this copy, the
numbering changed four times .
44
However, page numbering
could not be modified in a
disorderly manner because this
would generate considerable
difficulty for decoding operators.
Therefore, one had to adopt
a partially random order - for
instance ascending or descending
- and skip some numbers, as 7.10 First page of the Red Code dictionary
allowed by the fewer pages than
the thousand combinations between 000 and 999 .
45
Of course, experienced analysts, especially with the code in their hands, could identify an ordered
numbering of this kind.
In all codes, including paged ones, protection against decryption could be greatly increased by
adopting a ‘double-encoding’ or ‘overencoding’, achieved by transposing figures within each
group or by adding or subtracting numbers that could vary according to established keys. The
following chapters will illustrate the various methods adopted for trying to increase the Red Code
security after 1915, until the introduction, in the summer of 1917, of encoding-decoding tables that
resulted much more effective than mere overencoding to counter enemy decryption.

43 Such a trick, along with the skilful use of homophones - namely several groups corresponding to one letter, syllable or word
selected amongst the most frequent ones - would have made breaking the code much more difficult.
44 AUSSME, Series F2, env.28. In one specimen therein “Supreme Headquarters” is written.
45 This rule applies to any numbering in the examined codebooks. Some examples of numbering as follows: first example:
003, 008, 011, etc. up to 891, 893; second example: 929, 925, 919, etc. up to 091, 099.

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