The Double Playfair is an extension of the Playfair to use two separate keys and to encipher each pair of letters twice. The German police made the mistake in late 1941 of switching from the rather ...

Using the same methods for trying to locate the crib RED PENGUIN FRENZY, we note that it can be segmented either as then it's quite likely that the EDF is part of a column, and we can see all five ...