B5G-NFM: Blockchain-Based 5G Network Function Management With Enhanced Security and Privacy

Within the 5G Service-Based Architecture (SBA), the prevalent centralized frameworks, particularly those managing public key certificates and Network Function (NF) services, face significant security and privacy vulnerabilities due to their reliance on centralized Certificate Authorities (CAs) and Network Repository Functions (NRFs). This centralization in current 5G standards poses two critical issues. One is the risk of single points of failure associated with CAs and NRFs. The other is a substantial risk of privacy leakage in cross-domain NF access authorization. These issues underscore the demand for decentralized NF management with enhanced security and privacy. However, existing related schemes still suffer from such drawbacks as poor security and privacy, low efficiency, and a lack of automation in the management of NF certificates. In this paper, we propose B5G-NFM, a pioneering Blockchain-based 5G Network Function Management scheme designed to bolster security and privacy. B5G-NFM integrates a blockchain middleware network function, a decentralized protocol for managing NF public key certificates, and a decentralized mechanism for NF service discovery coupled with a privacy-preserving NF access authorization protocol. Our thorough security and performance assessment verifies that B5G-NFM not only meets its security and privacy goals, but also aligns with efficiency demand, marking a substantial progress in strengthening 5G network infrastructure.