4. Find a key for the affine linear cipher with alphabet {A, B, C, ... ,Z} and block length 3 that encrypts red as TWO. (To make it a bit more interesting, choose a matrix other than the identity, and a vector b different from the zero vector. Note that there are many different possibilities; use an easy one.) 4. Find a key for the affine linear cipher with alphabet {A, B, C, ... ,Z} and block length 3 that encrypts red as TWO. (To make it a bit more interesting, choose a matrix other than the identity, and a vector b different from the zero vector. Note that there are many different possibilities; use an easy one.)