(a) (i) If m = p·q·r where p, q, and r are prime numbers, what is Φ(m)?
(ii) Therefore, Determine Φ(440).
(b) Describe the following terms as used in cryptography:
(i) Avalanche effect
(ii) Stream cipher
(iii) Primitive root
(iv) Confusion
(v) Steganography ((c)
Suppose an elliptic curve encryption/decryption scheme. The cryptosystem parameters are E5(1,6) and G=(2,4). B's secret key is nB=2.
(i) Find B's public key PB.
(ii) A wishes to encrypt the message Pm=(0,2) and selects the random value k=2. Determine the ciphertext Cm.