ed that 5G core network will enable network mode V2X operation privacy. 5G security is going to define device-to-network authentication methods and transport; specify provisioning and storage of 3GPP credentials for devices; and specify network functions and protocols necessary for secure device operation within the operator network. The V2X architecture relies on the security relationship between device and its home operator network. In addition, secondary authentication schemes can support industrial and virtual private networks that wish to deploy their own authentication methods and credentials, thus it is possible to deploy public key infrastructure (PKI) A public key infrastructure (PKI) is a set of rules, policies, and procedures needed to create, manage, distrib- ute, use, store, and revoke digital certificates and manage public key encryption. In cryptography, a PKI is an arrangement that binds public keys with respective identities of entities. The binding is established through a process of registration and issuance of certificates at and by a certificate authority. 840 Chapter 7 security, where devices use a digital certificate to authenticate themselves to the network and vice versa. 5G security design is being developed to achieve the following goals [23]: Enhanced subscriber/device privacy: This is an improvement over LTE in that the new subscriber permanent identifier (SUPI) is never allowed to be transmitted over the air. Instead, the sensitive part of the SUPI is sent over the radio link protected against spoofing and tracking, which was not the case with the 3G/4G international mobile sub- scriber identity. Enhanced security support at the network level, along with capability for flexible authentication and authorization schemes: A new network function is specified, known as security anchor function (SEAF), which maintains the security anchor deep in a net- work (in a physically secure location). The SEAF also provides flexibility in deploying other network entities such as AMF and SMF. In Rel-