# An Introduction of a Modular Framework for Securing 5G Networks and Beyond
## 2 Related Work
### Security Mechanisms
#### 2.1.3 Access Rights Delegation  
Users can be assigned access permissions in the form of delegation, which is the process of assigning access rights to a user by either an administrative user or another user. The administrator user does not need to be able to use the access right, but a user delegation must be able to use the access right [25]. For authorisation and capability revocation management, a federated delegation method can be used in the capability development and propagation workflow. This could overcome issues in the access control strategy processing of a hybrid security mechanism by combining ABAC and CBAC with federated identity (FId) in a content-aware mobile network such as 5G [12]. Moreover, delegating some authentication and authorisation activities to other security domains facilitates 5G security policies and ubiquitous services access in different domains from multiple SPs. Processing capability validation in the HN and third-party SPs offers a D2D communications access control mechanism that is flexible, elastic, context-aware and fine-grained [26]. This inter-domain delegation and access authorisation enable 5G-enabled D2D communications security to be implemented beyond static authorisation.  
In addition, the authors in [27] introduced a framework that proposed a self-delegation protocol for device authentication and proactive handover authentication using a delegated credential for unified network- and service-level authentication for wireless access. Two authentication and key agreement protocols were introduced as part of a security framework to secure transactions at the network and service levels in [28]. In a heterogeneous system such as 5G for multi-server collaboration, privacy protection is crucial, as presented in [29], so the authors used blockchain to develop heterogeneous multi-access edge computing (MEC) systems to offer privacy topology protection. The authors in [30] developed a privacy-preserved, incentive-compatible and spectrum-efficient framework based on blockchain that considers human-to-human spectrum utilisation and machine-to-machine communication. A framework for the Internet of Vehicles (IoV) architecture model and an authentication-based protocol for smart vehicular communication using 5G are both suggested in [31].  
The comparison between some related work is shown in Table 1 in order to highlight the key differences between the other pre-existing security frameworks for heterogeneous networks security and the proposed conceptual framework in this research. It outlines the authors, their descriptions, and the variations among a number of criteria, including key hierarchy, protocols interface, privacy preservation, authentication, authorisation, single sign-on (SSO), formal verification and evaluation.  
As discussed in the related work, some security features such as authentication, authorisation and permission delegation have been used in different D2D communications or 5G independently. However, there has been a lack of a framework that considered a multilayered security solution for a 5G mobile network including the D2D communication as a layer of the network. With 5G's unique characteristics, the promise of integration with the networks and pushing services to the edge, the proposed framework intends to provide an integrated security solution for D2D communications in 5G and beyond that is interoperable, verified and evaluated.  
As discussed in the related works, some security features such as authentication, authorisation and permission delegation have been used in different D2D communications or 5G independently. However, there has been a lack of a framework that considered a multilayered security solution for 5G mobile networks, including D2D communications as a layer of the network architecture. With 5G's unique characteristics, the promise of integration with the networks and pushing services to the edge, the proposed framework intends to provide an integrated security solution for 5G and Beyond that is interoperable, verified and evaluated.