Which two messages complete the TLS 1.2 handshake before encrypted application data is exchanged?

• A. Finished and ServerFinished
• B. ClientKeyExchange and ChangeCipherSpec
• C. Certificate and ServerHelloDone
• D. ClientHello and ServerHello

Answer: (A)

In TLS 1.2, the handshake is considered complete only after both sides have exchanged Finished messages. These Finished messages carry a MAC over the entire handshake transcript, created with the keys and algorithms negotiated earlier. Verifying these Finished messages proves that both parties have the same handshake history, and that the derived session keys are correct. Once the client sends its Finished and the server responds with its own Finished, the connection transitions to encrypted application data using the negotiated cipher suite and keys.

The other steps happen earlier in the handshake: initial hello messages establish parameters, certificates exchange authenticates either party, and key exchange plus ChangeCipherSpec prepare for encryption. But they do not signify the final confirmation of a successful handshake the way the Finished messages do.