The change cipher spec protocol is used to change the encryption being used by the client and server. It is normally used as part of the handshake process to switch to symmetric key encryption.

What happens in change cipher spec?

The “Change Cipher Spec” message lets the other party know that it has generated the session key and is going to switch to encrypted communication. The “Finished” message is then sent to indicate that the handshake is complete on the client side.

What is TLS change cipher spec?

Change Cipher Spec is a separate sub-protocol in TLS which is used to indicate either party in TLS negotiation that the subsequent messages will be sent encrypted using the negotiated key and algorithm.