It's beyond the realm of possibility that any German intelligence agency would have been using single transposition in 1941.
Or not!
I was reading David Kahn's "The Reader of Gentlemen's Mail" - his biography of Herbert Yardley. In 1941, Yardley was working with the Canadian government, helping them set up a crypto bureau. Most of what they were cracking were messages to German spies working in South America - and yes, they really were using a simple transposition cipher, just like had been appearing in puzzle books for decades.
I've posted it over there, I'll post it here.
Read section 12-3 of FM 34-40-2:
http://www.umich.edu/~umich/fm-34-40-2/ch12.pdf
This technique of solving incomplete columnar transposition ciphers had been described in the open literature prior to 1941.
It was described in Helen Gaines' "Elementary Cryptanalysis", published in 1939. Many of the techniques in Gaines' book originated in M.E. Ohaver's column "Solving Cipher Secrets", in "Flynn's Weekly Detective Fiction" magazine, which ran from 1924 to 1928. I'd not be at all surprised to find that this technique was described there.
It's beyond the realm of possibility that any German intelligence agency would have been using single transposition in 1941. It's not at all impossible to believe that someone at the FBI, asked to create a worksheet for a Life photo-op that didn't reveal anything of substance, would choose to demonstrate the cryptanalysis of a cipher that was already widely-known among the well-informed amateurs. and hence wouldn't compromise any of the systems the Germans were actually using, or how effective they were at breaking them.
It is possible that this was a partial setup, but in this case it was the question of a deception message that was about to be sent using encryption that was probably already blown at the time.
Yep.
The worksheet shows the cryptanalysis of a simple transposition cipher using a technique that was included in Helen Gaines' "Elementary Cryptanalysis", published in 1939.
Whether it was ever a secure cipher I can't say. But by the late 30's, it was appearing in the advanced puzzle magazines.
Monster Grendel's tastes were plainish
Breakfast just a couple Danish...
(Maurice Sagoff)
"Unibus timeout fatal trap program lost sorry" - An error message printed by DEC's RSTS operating system for the PDP-11