Privacy-aware Secure Authentication and Handover Protocols for 5G-enabled Mobile Communication

The evolution of mobile communication has facilitated technological advancements that enable seamless global connectivity. With the advent of 5G technology, wireless communication has taken a significant leap forward, promising unparalleled speed, capacity, and connectivity. As we enter this era of advanced communication, we also need to consider its implications for security and privacy. The integration of 5G technology brings new opportunities and challenges, making it essential to thoroughly examine the security and privacy frameworks that support this advanced network. Compared to the previous mobile communication generations, 5G offers a more robust security infrastructure by strengthening two key protocols: Authentication and Key Agreement (AKA) and Handover (HO). Although 5G-AKA significantly improves security measures, it is worth noting that the current protocols lack support for several essential security and privacy properties, such as forward secrecy, forward privacy, and unlinkability. Thus, a critical need remains to address these gaps to ensure comprehensive protection in 5G networks.

In response to the issues in respect of security and privacy, this thesis proposes three novel AKA and HO schemes. The three proposed schemes have different security and privacy goals that support improved security and privacy features compared to the conventional 5G-AKA and HO protocols currently utilized and other existing solutions. In particular, we examine challenges associated with integrating ultra-dense small cell networks (SCNs) into the 5G infrastructure. This exploration led us to investigate the concept of region-based handovers and to propose, to the best of our knowledge, the first scheme that provides privacy-preserving, secure inter-region-based AKA and HO scheme. This scheme provides secure authentication for roaming users with an efficient and seamless handover process. To enhance security and privacy measures further, we undertake an additional investigation into fortifying resilience against key compromise impersonation attacks. This involves proposing a novel, secure, privacy-preserving Universal Handover scheme (UniHand) tailored for SCNs within the 5G mobile communication framework. Finally, in pursuit of seamless compatibility with 5G networks, we introduce an improved iteration of the 5G-AKA and HO protocols. Referred to as Pretty Good User Privacy (PGUP), this novel symmetry-based scheme aims to mitigate security and privacy vulnerabilities inherent in the existing 5G-AKA and HO protocols while maintaining high compatibility with the 5G infrastructure.