TheCodeBreakers
Washington in February of 1920. He quit after six months when he
finally realized the espionage nature of the work, but by then Livesey had
accomplished the almost unheard-of feat of learning Japanese in that
time.
Yardley called the first code "Ja," the "J" for Japanese, the "a" a serial
for the first solution. From 1919 to the spring of 1920 the Japanese
introduced eleven different codes, having employed a Polish expert,
Captain Kowalef-sky, to revise then" cryptologic systems. Kowalefsky
taught the Japanese how to bi-, tri-, and tetrasect their messages: to
divide them into two, three, or four parts, shuffle the parts, and then
encipher them in transposed order to bury stereotyped beginnings and
endings. Some of the codes contained 25,000 code groups.
During the summer of 1921, the Black Chamber solved telegram 813
of July 5 from the Japanese ambassador in London to Tokyo. It
annaabi.ee 
