What occurs when the client and server send a message to Change Cipher Spec?

• A. They start using a new public-private key pair
• B. They begin using session keys derived from the Master Secret
• C. They initiate a new encryption process
• D. They terminate the current session

Answer: (B)

When the client and server send a message to Change Cipher Spec, they begin using session keys derived from the Master Secret. This message serves as a signal that the parties are transitioning to a new state where they will communicate using these newly agreed-upon cryptographic parameters.

The Change Cipher Spec message is part of the TLS/SSL handshake protocol, which is designed to establish a secure connection. During the handshake, the Master Secret is generated through a key exchange process, and from this Master Secret, session keys are derived that will be used to encrypt the data during the session. By sending the Change Cipher Spec message, both the client and server confirm that they are ready to switch to the new session keys and start encrypting data using these keys, ensuring the integrity and confidentiality of the transmitted information.

It is important to understand that while other options may mention different aspects of cryptography and sessions, they do not specifically describe the transition to using the derived session keys as initiated by the Change Cipher Spec message.