Reply To: The official Challenge 9B hints thread

[id-hkj]

The polybius square used to encrypt it was as below:
1 2 3 4 5
1 Z E R O P
2 Q S T U V
3 W X Y A B
4 C D F G H
5 I K L M N
The keyword for that was ‘ZERO’

The thing that you had to subtract at the start was 55 14 23 45 51 55 44 – if you put that into the square, it gives you:
NOTHING