NOVA Online | Decoding Nazi Secrets | Hint for Double Playfair Cipher

Hint for Double Playfair Cipher
Back to Double Playfair Cipher

This cipher is quite difficult with the amount of information available here. Wartime cryptanalysts expected to be able to solve for the keywords after 150 to 200 plaintext-ciphertext pairs were established. Solving this problem probably requires trial and error to guess the correct period for segmenting the message, and also to guess which key was re-used.

The second square of the Double Playfair used one of the keys listed as possible duplicates: BRIGHTONROCK, in left-to-right rows. The period chosen is 15, so that the cipher is broken up into pairs thus:

	TIPPOYNOYBYAKLP
	YNKQTESIOORKSSP

	ZDASPMMPNPYITQB
	COYLOXNPXTCTYYO

	ZBGPSZCXCQLICDP
	RIMLEKTRRGEKRMP

	RBXYQMATFMXYLQI
	TNWWGDYGVFESLNI

	GWQGENDNODMPTXK
	IRIFVGNIBTDTYNB

	UEWPPS
	XMPKWT

This means the last groups correspond to:

	-MESSA
	GEENDS