Many books have been written of recent years about Bletchley Park and the British cracking of the German Enigma ciphering machine, and the dissemination of Ultra intelligence. The story of similar work against the Japanese communication network is less know, and the story of Australia involvement even less so. Secret Code-breakers of Central Bureau addresses this hitherto unknown history, correcting aspects of the story where US claims were unwarranted, and identifying key players in the Australian sphere. An interesting aspect is Dufty’s portrayal of the inter-personal and inter-service rivalries that coloured many of the activities. War is messy, and personalities under stress don’t necessarily successfully subjugate their personalities to the corporate good. This is a fascinating focus on Australia code-breaking, deciphering, and traffic analysis activities during World War 2.