Information Security20795 marksNumerical: Hill cipher decryptionHill cipher and matrix operations
Decrypt the cipher text "CRHG" using the Hill cipher with the key matrix .
Decrypt the cipher text "CRHG" using the Hill cipher with the key matrix $$\begin{bmatrix} 3 & 4 \ 3 & 5 \end{bmatrix}$$. [5]
- Ciphertext: CRHG - Key matrix: $K = \begin{bmatrix} 3 & 4 \ 3 & 5 \end{bmatrix}$ - Alphabet mapping: A = 0, B = 1, ..., Z = 25 - Modulus: 26 C R H G ------------ 2 17 7 6 Column vectors: $\begin{bmatrix}2\17\end{bmatrix}$, $\begin{bmatrix}7\6\end{bmatrix}$ $$\det(K) = (3)(5) - (4)(3) = 15 - ...