Extract relating to military intelligence work:
In August , while in Auckland, he unexpectedly received an invitation to apply for the Chair of Greek in the University of Sydney, which had been recently vacated by J. Enoch Powell, who had returned to England at the approach of war in Europe. He accepted the invitation, and thus, at the outbreak of the Second World War, Dale was established in Sydney. ...
Early in 1941, however, with the Japanese threat growing, Trendall and three other academics (‘men of the professor type’) from the University of Sydney (T. G. Room, Professor of Mathematics; R. J. Lyons, Senior Lecturer in Mathematics; and A. P. Treweek, Lecturer in Greek) were approached by a representative of the Chief of the Australian General Staff to see if they would be willing to help with the decoding of Japanese signals. The group got together informally to study available books on cryptography and to work on Japanese diplomatic messages supplied by the Army. During this period they succeeded in breaking the Japanese LA-code, a low-grade code used for consular messages. Room, Lyons, and Treweek moved to Melbourne the same year to join the Signals Intelligence Organisation set up by Captain Eric Nave. Trendall was transferred early in 1942, and proved to be exceptionally gifted as a cryptographer. He headed a small group working out of Victoria Barracks in St Kilda Road, a group that specialised in decrypting Japanese diplomatic signals. In later years, however, he was very reticent about this period of his life, and he was very reluctant to talk about his own accomplishments.
6. See David Jenkins, Battle Surface! Japan’s Submarine War Against Australia, 1942-44 (Sydney, 1992), pp. 42-3, 157-9.