I came across this in the book The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet by the historian David Kahn. I'm afraid I haven't got my copy to hand at the moment, but there seems to be a very reasonably priced Kindle version.
(I'm now half panicked that I might have misattributed to Shannon something that was actually Friedman; both of which feature in the book. The uniqueness point concept seems so obviously information-theoretic to me that I might have made the connection by mistake, it's a while since I read that chapter.)
(I'm now half panicked that I might have misattributed to Shannon something that was actually Friedman; both of which feature in the book. The uniqueness point concept seems so obviously information-theoretic to me that I might have made the connection by mistake, it's a while since I read that chapter.)