Novel Protocols to Mitigate Network Slice Topology Learning Attacks and Protect Privacy of Users' Service Access Behavior in Softwarized 5G Networks

In the softwarized fifth generation (5G) networks, authentication protocols are deployed by both the mobile network operators and the third-party service providers to enable secure slice formation at the network side and user validation at the service provider side, respectively. However, the usage of static key-based authentication protocols in 5G networks gives rise to two major problems: (i) network slice topology learning attack during the formation of slice and (ii) exposure of users' service access behavior to the third-party service providers and device-to-device communication peers. In this paper, we propose group anonymous (i) privacy preserving mutual authentication (PPMA) and (ii) privacy preserving one-way authentication (PPOA) protocols to address the aforementioned problems, respectively. We also prove the security of the PPMA and PPOA protocols against the chosen ciphertext attack in the random oracle model. The PPMA and PPOA protocols are implemented using the JPBC library and the computation overhead is measured. For 1024 bits discrete logarithm security, the computation overhead of the PPMA and PPOA protocols is respectively 48.54% and 68.65% lower than an existing privacy preserving authentication protocol on an Intel processor. The PPMA and PPOA protocols are generic and can be applied in peer-to-peer authentication scenarios where group anonymity and privacy preservation are considered.