Consider the SSL protocol in Figure 10.4.

A.) Suppose that the nonces RA and RB are removed from the protocol and we define K = h(S). What effect, if any, does this have on the security of the authentication protocol?

B.) Suppose that we change message four to HMAC(msgs,SRVR,K). What effect, if any, does this have on the security of the authentication protocol?

C.) Suppose that we change message three to {S}Boh, h(msgs,CLNT,K). What effect, if any, does this have on the security of the authentication protocol?

Can we talk?, cipher list, RA Certificate, cipher, RB {S)Bob, E(h(msgs,CLNT,K),K) h(msgs,SRVR.K) Alice Data protected-ith keyK Bob Figure 10.4: Simplified SSL