Reply To: Challenge 10B
To confirm my use/recommendation of using Excel, this is the table I used to finish off 10B (no surprise there!). The decryption used two straightforward formulae working on pairs of ‘cards’ to give the plaintext equivalents. The major advantage of this method was the interactive aspect of filling in the lower-case pairs, one by one, giving instant feedback as to its effect on the emerging plaintext: starting with 2C-KS returning t-h. Then working on the likely pairs, as dictated by the digram probabilities.
0 1 2 3 4 5 6 7 8 9
0 AC 2C 3C 4C 5C 6C f u l h
1 7C 8C 9C XC JC QC e a r t
2 KC AD 2D 3D 4D 5D b c d g
3 6D 7D 8D 9D XD JD i k m n
4 QD KD AH 2H 3H 4H o p q s
5 5H 6H 7H 8H 9H XH v w x y
6 s h a d o w JH QH KH AS
7 b c e f g i 2S 3S 4S 5S
8 k l m n p q 6S 7S 8S 9S
9 r t u v x y XS JS QS KS