In the German Wikipedia entry on dr Werner Weber there is a mistake.
During WWII Weber worked at OKW/Chi (Oberkommando der Wehrmacht/Chiffrier Abteilung – Codebreaking department of the Supreme Command of the Armed Forces) and he solved important Japanese diplomatic cipher systems.
The first major system solved was the transposed code J-19 FUJI, used in the period 1941-43. Although some TICOM reports state that he was unable to solve the successor to FUJI this is not correct.
The next main system was also a transposed code (Japanese designation TOKI) and it was solved in the period 1943-45 by OKW/Chi and by the Pers Z agency (decryption department of the German Foreign Ministry).
Why did some Germans say in postwar interrogations that they could not solve it? I don’t know.
Why did the Allied interrogators believe them? I don’t know.
Just clearing things up…