Enhancing trust and liability assisted mechanisms for ZSM 5G architectures

5G improves previous generations not only in terms of radio access but the whole infrastructure and services paradigm. Automation, dynamism and orchestration are now key features that allow modifying network behaviour, such as Virtual Network Functions (VNFs), and resource allocation reactively and on demand. However, such dynamic ecosystem must pay special attention to security while ensuring that the system actions are trustworthy and reliable. To this aim, this paper introduces the integration of the Manufacturer Usage Description (MUD) standard alongside a Trust and Reputation Manager (TRM) into the INSPIRE-5GPlus framework, enforcing security properties defined by MUD files while the whole infrastructure, virtual and physical, as well as security metrics are continuously audited to compute trust and reputation values. These values are later fed to enhance trustworthiness on the zero-touch decision making such as the ones orchestrating end-to-end security in a closed-loop.