Answer:
Explanation:
Given Alice's RSA public key (N, e) = (33,3) and Alice's private key is d = 7.
a)
To encrypt: Formula C= M^e mod n = 19^3 = 28 (mod 33) therefore C = 28
To decrypt: Formula M = C^d mod n = 28^7 = 19 (mod 33) therefore M = 19 getting back our original answer proving Alice can decrypt C to obtain M
b) The signed result is Formula S = M^d (mod N) = 25^7 (mod 33) = 31. To verify the signature, Bob computes Formula
S^e (mod N) = 31^3 (mod 33) = 25 therefore the signature is verified as the result matches the received value, M which was 25.