TheCodeBreakers
Yet this basic system—the adding of a key to a checkerboard
substitution, though with important improvements—survived through
the years to become the primary form of secret communication for
Russian undercover agents.
The Russian plan of campaign against Germany in 1914 called for an
invasion of East Prussia by two armies. The 1st Army was to drive
straight west into that province and grip the German defenders tightly in
battle. The 2nd Army, to the south, was to circle around the Masurian
Lakes, come up behind the Germans, block their retreat, and destroy
them. This strategy naturally required careful timing and close
collaboration between the two forces. Unfortunately, Russian
communications were woefully inadequate. The 2nd Army had only 350
miles of wire all told to string during its advance across the plains of
Poland; this pitiful supply contrasts sharply with the 2,500 miles of wire
later used in a single day by an A.E.F. army on the Western Front. At the
annaabi.ee 
