Abstract Algebra: Theory and Applications · Problem 7.4.6

Algebraic Coding Theory — Thomas Judson

Mathematics — Abstract Algebra · polyalphabetic-encryption-matrix

Problem

Given the matrix

A = \begin{pmatrix} 3 & 4 \\ 2 & 3 \end{pmatrix},

use the encryption function

f(\mathbf{p}) = A\mathbf{p} + \mathbf{b}

to encode the message CRYPTOLOGY, where

\mathbf{b} = (2, 5)^t

. What is the decoding function?