## 4 Security Challenges and Solutions in 5G Network and LPWAN-IoT
### Security Challenges and Solutions in LPWAN-IoT and 5G
#### 4.2.2 Security Challenges and Solutions in 5G  
Consequent to the 5G security challenges highlighted involving mobile/virtual operations, telecommunications fraud, the IoT, the Internet of Vehicles (IoV), and the SDN, the 5G Public-Private Partnership (5 GPPP) Security Working Group introduced to research on security architecture, access control, privacy protection, trust models, security monitoring and management, network slicing security isolation, including other aspects [73]. The next-generation mobile network (NGMN) advocates for user authentication, user privacy protection, and network security, including other aspects [66]. Hence, 5G requires a new security mechanism for new applications, new network architecture, and new air interface technologies. Security is required to authenticate massive device-to-device communications, provide high availability, and support low latency, and low energy consumption for IoT applications. The advent of new technologies such as SDN/NFV, MEC, and other new technologies introduced some changes and security risks. Yet, the existing 4G/LTE-A security architecture and security key technologies are unable to address these new security problems. Thus, these security issues caused by enormous application scenarios and new technologies pose new challenges for the design of 5G security architecture. The 5G security architecture has been envisioned to support numerous application scenarios as well as a unified authentication mechanism and network slice security including user privacy protection. The 3 GPP Working Group-SA3 is responsible for the design of 5G security architecture. The SA3 has enacted that 5G security architecture design and key hierarchy should encompass the basic form [74] as depicted in Figure 6. The simplified 5G architecture of the 5G System involving only the security-related functions is shown in Figure 6. The Abbreviation gives the descriptions of terms including the 5G key hierarchy abbreviations. Generally, a 5G System consists of the radio access network (RAN) and the core network. The RAN comprises the Next Generation Node B (gNB) which serves as the 5G base station. The core network contains the functions for the management/delivery of the diverse services to the UE or device. The core functions include the authentication server function (AUSF), the access and mobility function (AMF), and the unified data management (UDM) function which stores the user profiles. 5G network security features can be categorized into two groups. In the first group, all the features secure the communication between the UE and the network OTA interface to the base station. The other group is meant for features that secure the communication between the different network functions such as between the RAN and the core network, which are the backhaul network interfaces. Also, between the UE and the network, security is provided at two levels or strata. The first level is the access stratum (AS) that protects the control plane (CP) and user plane (UP) between the UE and the gNB transmitted over the packet data convergence protocol (PDCP). The second level is the non-access stratum (NAS) that protects the CP between the UE and the core network transmitted over the NAS protocol. A run of the primary authentication (PA) procedure is required for mutual authentication between the UE and the network to be successfully carried out [76]. 5G supports two sets of this authentication. The first one is an enhanced version of the authentication and key agreement procedure (AKA) or 5G-AKA, which was developed to support a procedure called the generic bootstrapping architecture (GBA) [72] in the earlier network release. The second one is an EAP-based procedure called EAP-AKA [77] and was developed to support LTE authentication of UEs over the non-cellular type of access networks such as WLAN, and LPWAN. This second set of authentications is the secondary authentication procedure.