A Japanese diplomat wrote shortly after World War II that Japan's theoretical and technical knowhow on encrypting sensitive information was woefully underdeveloped during the hostilities, declassified diplomatic records Thursday showed.

Kazuji Kameyama, who had previously headed the telegram division of the Foreign Ministry, wrote in December 1945 that Japan would face "a tremendous disadvantage" in the international arena if it were left behind in this area amid rapid advances in other countries' encryption technology.

Kameyama, then a counselor at the Japanese Embassy in Moscow, reflected on how Japan was outsmarted by the United States, which managed to intercept and decipher its coded messages exchanged between the ministry and diplomatic missions abroad during the war.

He proposed that Japan immediately "take advantage of the lesson it had drawn from its abject failure in the past."

Specifically, Kameyama called for setting up a research center to improve Japan's encryption technology and facilities to make necessary prototype cipher machines and promoting the training of technicians.

Kameyama later served as the first mayor of Seki, Gifu Prefecture.