In September 1942, an error by the Japanese gave clues to the code-breakers at Kilindini and, by November 1942, they were able to read all previous traffic and break each message as they received it.
An error by the Japanese gave clues to the code-breakers at Kilindini. This was in September 1942. They were able to read all previous traffic and break each message as they received it. This was by November 1942.