This exercise is from Introduction to Modern Cryptography (2nd Edition) by Katz & Lindell

Let F be a pseudorandom function and G be a psuedrandom generator with expansion factor 1(n) n +1. For each of the following encryption schemes, state whether the scheme has indistinguishable encryptions in the presence of an eavesdropper and whether it is CPA-secure. (In each case, the shared key is a uniform k E 0, 1]".) Explain your answer (a) To encrypt m E {0, 1)"+1, choose uniform r {0, 1)" and output the ciphertext(r, G(r)m). (b) To encrypt m E {0, 1}2n, output the ciphertext m D Fk(On). (c) To encrypt m E 10, 1^2n, parse m as m1| m2 with m1- m2|, then choose uniform r 10,1)" and send r, mi F. (r), m2Fe(r + 1)