<story><title>A Canadian opens up about her secret wartime work, eavesdropping on Japan</title><url>https://www.cbc.ca/news/politics/second-world-war-marjorie-stetson-japan-1.6239427</url></story><parent_chain></parent_chain><comment><author>bell-cot</author><text>Summary:  The subject (of the article) was a very routine SIGINT sergeant in WWII.  She worked in Canada, listening on the radio to (Imperial) Japanese military signals.  She wrote those down on paper, then (in effect) mailed the paper to the next stage of the SIGINT pipeline.  The signals were encrypted (by the Japanese) - so she had no way to tell whether one said &amp;quot;Our big attack with force X against location Y will happen at time Z&amp;quot;, or &amp;quot;Our garrison on Useless Island is still bored.&amp;quot;&lt;p&gt;While on paper this was all super-secret, and such dull work was very important to the war effort...the Japanese knew that the allies had loads of SIGINT radio operators like her, doing jobs just like hers.  And nothing she knew would have been of much value to them.&lt;p&gt;For me, all the CBC article&amp;#x27;s hype about super-duper secrecy just messes up what could have been a much better human interest story.</text></comment>
<story><title>A Canadian opens up about her secret wartime work, eavesdropping on Japan</title><url>https://www.cbc.ca/news/politics/second-world-war-marjorie-stetson-japan-1.6239427</url></story><parent_chain></parent_chain><comment><author>vmh1928</author><text>A good book that describes the information provided to allied leaders via the intercepts and decryption of the Japanese diplomatic Purple codes is given in the book &amp;quot;Marching Orders&amp;quot; by Bruce Lee.  ISBN 0-517-57576-0 (c.1995)
Lee had access to 1000&amp;#x27;s of the daily decryption and analysis summary reports (called Magic Summaries,) and  provided to the president, Marshall and others.  He provides an almost day-by-day chronology showing what the leaders knew and how that knowledge shaped their decisions about the conduct of the war.  [edit: the axis decrypts were called Ultra. Allied leaders had access to reports on both.]</text></comment>