For the Protocols 1, 2, 3, and 4, given below, determine which of the following five security services are being implemented and which are not implemented. In each case, explain why. 

Services:

C – Confidentiality,

AS – Authentication of the Sender,

AR – Authentication of the Receiver,

NS – Non-repudiation of the Sender, and

NR – Non-repudiation of the Receive

Protocol 1

1. A sends to B

A, E(PUB, M), h(M || A || B), B

2. B sends to A

B, h(M || B || A), A

Protocol 2

1. A sends to B

A, E(PUB, M), E(PRA, h(M || A)), B

2. B sends to A

B, E(PUA, h(M || B)), A

Protocol 3

1. A sends to B

A, E(PUB, K), E(K, M), E(PRA, M || A), B

2. B sends to A

B, h(K || M || B), A

Protocol 4

1. A sends to B

A, M, E(KAB, h(M || A)), B

2. B sends to A

B, h(M || B), A

Notation:

X represents a unique name of user X, where X=A or B

M means a message

V || W means V concatenated with W

KAB means a secret key shared in advance by A and B

K means a session key, generated at random as a part of a given protocol

E(PUY, Z) means Z encrypted using a public key of Y

E(PRY, Z) means Z encrypted using a private key of Y

E(K, Z) means Z encrypted using a secret key K