Reply To: !
@Gen_ruikt
You don’t need to how exactly determinants or inverse matrices work in order to be able to decrypt a hill cipher. But an inverse matrix works like any other inverse, it “undoes” an operation, and the determinant is just something you use to find the inverse.
So encryption is like multiplying your ciphertext block entries by some matrix K, and to undo the operation, you multiply the the blocks by the inverse of K to get back to the plaintext.
My first year of doing the cipher challenge, I had no clue what the hill cipher was or how matrices worked, so you’re already in a good position if you can see how the process works by looking at the numbers!