A Blockchain-Based Approach for USIM Management in Mobile Networks

Universal Subscriber Identity Module (USIM) is an essential part of the mobile network mainly for providing identification and authentication of the subscriber. The activation and deactivation of USIMs are the two most critical services that must be supported by Mobile Network Operators (MNOs). The current solutions suffer from several limitations such as the lack of round-the-clock services and the presence of a single point of failure. In this paper, we propose a blockchain-based scheme for USIM management. Each MNO creates its own smart contract and publishes its address to subscribers. Subscribers can then directly submit their requests by registering a transaction that invokes a specific function of the smart contract. The proposed scheme provides an anytime-anywhere service while at the same time it leverages the benefits of blockchain technology, such as a decentralized architecture that prevents Denial-of-Service (DoS) attacks, as well as a secure auditable log and payment using cryptocurrency. Moreover, we provide a security proof for the scheme through formal verification. Our results demonstrate that our scheme ensures subscriber privacy while providing mutual authentication among participants. Finally, our evaluation on the Ethereum blockchain confirms the efficiency of the scheme in terms of both transaction and execution costs.