There may be some new documents available now, but the story as such seems to have been known for a while. I first learned of it last summer while reading some

There may be some new documents available now, but the story as such seems to have been known for a while. I first learned of it last summer while reading some of the drafts for Ross Anderson's update of his excellent Security Engineering. See chapter 26, https://www.cl.cam.ac.uk/~rja14/book.html https://www.cl.cam.ac.uk/~rja14/book.html