Given two matrices M$=(\{2,3,2\},\{0,2,1\},\{3,0,1\})$ and N$=(\{2,23,25\},\{3,22,24\},\{20,9,4\})$ where each row of the matrix is listed in the curly braces.

$($a$).$ Verify that M x N mod $26=$ N x M mod $26=$ I $($identity matrix$)$

$($b$).$ Use Hill cipher to encrypt the message "matrix" using matrix M as the Key