BC-AKA: Blockchain based asymmetric authentication and key agreement protocol for distributed 5G core network

Secure authentication between user equipment and 5G core network is a critical issue for 5G system. However, the traditional authentication protocol 5G-AKA and the centralized key database are at risk of several security problems, e.g. key leakage, impersonation attack, MitM attack and single point of failure. In this paper, a blockchain based asymmetric authentication and key agreement protocol (BC-AKA) is proposed for distributed 5G core network. In particular, the key used in the authentication process is replaced from a symmetric key to an asymmetric key, and the database used to store keys in conventional 5G core network is replaced with a blockchain network. A proof of concept system for distributed 5G core network is built based on Ethereum and ECC-Secp256k1, and the efficiency and effectiveness of the proposed scheme are verified by the experiment results.