The matrix theory is used in the ___ technique

a) hill cipher

b) monialphabetic icpher

c) playfair cipher

d) vignere cipher

The matrix theory is used by hill cipher.

Explanation:

Th technique which uses matrix theory is hill cipher technique.

Hill cipher technique is a polygraphic substitution cipher and it is based on linear algebra.

For encrypting a message in Hill Cipher technique each block of n letters is multiplied by an invertible matrix of nxn and that to against modulus 26 and for the decryption of the message, every block is multiplied by the inverse of the matrix that was used for encryption.