Shared session key establishment using a Key Distribution Center (KDC). Using the following table, illustrate how Alice can initiate a secure session with Bob with the help of KDC. Here, KEKs are the long term key establishment keys used to transport the session keys across the network securely. Assume the encryption process to be as follows: Block (LB || RB) is 8 bits; Encryption Key (LK||RK) is 8 bits; Ciphertext = LC|| RC where LC=LB RK; and RC=RB LK.

For example, if plaintext=A7 (Hexa) and Key = 6D; then LC=A D = 1010 1101 = 0111 = 7 (Hexa); and RC = 7 6 = 0111 0110 = 0001 = 1 (Hexa); so Ciphertext = 71 (Hexa).

To decrypt, it does the reverse operation: Given ciphertext of C=LC||RC, it finds plaintext B=LB||RB, by finding LB=LC RK and RB = RC LK. Fill in the values at "??" below.

Alice	KDC	Bob
KEK: kA = D6 (hexa)	KEK: kA = D6 (hexa); kB = A8(hexa);	KEK: kB = A8 (hexa);
Alice sends a message to KDC requesting a session key between Alice and Bob
	Generate a random session key: kses = 7B (hexa);
	yA = ekA(kses) = ??
	yB = ekB(kses) = ??
KDC sends yA = ?? to Alice
	KDC send yB = ?? to Bob
Decrypt yA to derive kses using kA = ??		Decrypt yB to derive kses using kB = ??
Message to send, m = 45 (Hexa)
Encrypyt m using session key, y = ekses(m) = ??
Alice sends y = ?? to Bob
		Decrypt y using session key to get m = ??
		Verify that this is the message sent by Alice