Securing 5G Slices using Homomorphic Encryption

Network slicing is a powerful tool that provides 5G and future networks a robust means for managing cross-application QoS, dynamic traffic migration in response to network events, and in-network data aggregation and computation. Unfortunately, slicing inherits many of the security challenges of cloud and edge computing such as side-channel information leakage, while also encountering new challenges posed by multidomain authorization and quantum computing. Many extant mechanisms, such as PKI, are insufficient in the face of quantum computers, and existing side-channel mitigations impose heavy overhead costs while only providing defense against known attacks. In this paper, we describe a novel approach to protecting slice control information through the use of Homomorphic Encryption (HE). HE allows quantum-resilient validation and distribution of critical information, while also enabling hierarchical control across multiple domains and providing encrypted computation. Further, threshold HE enables secure decryption and computation of control or measurement information, while protecting the entire slice against potential key-leakage by rendering any one key useless without the required quorum. The benchmark results shown demonstrate that the HE mechanisms used can be deployed in a practical manner, providing stalwart security guarantees against a variety of threats.