Hint #2 for Playfair Cipher Back to Hint #1 Using the same methods for trying to locate the crib RED PENGUIN FRENZY, we note that it can be segmented either as RE DP EN GU IN FR EN ZY or ...

Thouless’s Passage I used the well-known Playfair cipher which was quickly solved after being made. The keyword was “SURPRISE”, with the plain text coming from Shakespeare’s Macbeth.

Like the Playfair, the Double Playfair cipher uses 5x5 squares. In this case two keywords are chosen, and each square is filled in the same way as the Playfair.