The final hint for Challenge 10A

[Harry]

The final hint for Challenge 10A

 

To start deciphering the message you convert the text to numbers with A->0, B-1 and so on

So the start reads

HHIZR KHHXH

which encodes as

7, 7, 8, 25, 17, 10, 7, 7, 23, 7

Now we group these into vectors

(7,7)

(8,25)

(17,10)

(7,7)

(23,7)

We then multiply these vectors by the 2×2 matrix we found last time, given by the string 2,-1,-1,1)

(7,7)-> (2*7-1*7, -1*7+1*7) = (14-7, -7+7) -> (H,A)

Any guesses what comes next?(8,25) -> (2*8-1*25, -1*8+1*25) = (16-25, -8+25) = (-9, 17) = (17,17) -> (R,R)

We leave it to you to complete the decryption!

Hope you enjoyed it!

Harry and Jodie