14. Consider equation (5.3){ h(K, M') = h(K, M, X) = F(h{K, M),X),}

a. Show that the equation holds if K, M, and X are all multiples of the hash block length (commonly, 64 bytes).

b. For which other sizes of K, M, and X does the equation hold?

c. Show that equation (5.4) holds for any size of M, M', and K, provided that h{M) = h(M').