The SSL handshake is a multi-phase process that establishes a secure communication channel between a client and a server.
Phase 1: Initial Greeting - Client and server exchange a 'hello' message to establish the SSL version, cipher suites, and session ID. The server selects an encryption algorithm.
Phase 2: Server Authentication and Key Exchange - Server proves its identity with an authentication certificate, sends its public encryption key, and may request client authentication.
Phase 3: Client Verification and Key Sharing - Client verifies the server's certificate, sends its own certificate if needed, and securely transmits a secret private key.
Phase 4: Finalizing the Secure Connection - Both parties confirm the encryption settings, cipher functions, and establish a shared secret for the rest of the session.