SSL was originated by Netscape; it consists of several upper layer protocols5 by which a pair of users – the Client and the Server – agree on a key exchange method, an encipherment algorithm, and a message digest.
In what follows we go through the Handshake Protocol initiated by a client.
Phase 1 – Client Initiation The Client proposes the following (Fig. 18.11).
Phase 1 – Server Response to Client_Hello: The Server accepts one of the choices made in the Client_Hello messages (Fig. 18.12).
Phase 2 – Server Authentication and Key Exchange: The Server delivers its certificate; when authentication/secrecy is enabled there is a key exchange. The Server requests a certificate from the Client (Fig. 18.13).