The correct answer is: C. rfc 7452
The core of the protocol is specified in RFC 7452, which is titled “The Transport Layer Security (TLS) Protocol Version 1.2”. This RFC defines the TLS protocol, which is a cryptographic protocol that provides communication security over a computer network. TLS is used to secure a wide variety of applications, including web browsing, email, and instant messaging.
RFC 7452 defines the TLS protocol in detail, including the handshake protocol, the record protocol, and the application data protocol. The handshake protocol is used to establish a secure connection between two parties. The record protocol is used to encrypt and authenticate data that is transmitted over the secure connection. The application data protocol is used to carry application data over the secure connection.
RFC 7452 is a widely used and well-respected standard. It is used by a wide variety of applications and is supported by a wide variety of software and hardware.
The other options are incorrect because they do not define the core of the TLS protocol. RFC 7254 defines the TLS 1.1 protocol, RFC 7252 defines the TLS 1.0 protocol, and RFC 7524 defines the TLS 1.3 protocol. These RFCs are all important documents, but they do not define the core of the TLS protocol.