Secure End-to-End VoLTE Based on Ethereum Blockchain

Voice over Long Term Evolution (VoLTE) technology defines standards to deliver real-time services such as voice and video over LTE based on IP Multimedia Subsystem (IMS) networks. The security implementation in VoLTE is End-to-Access (e2a), which means that the sessions are only encrypted between the mobile terminals and the IMS network. In this paper we propose a new approach for securing End-to-End (e2e) VoLTE media based the Ethereum Blockchain. The solution consists of creating public and private keypairs for VoLTE user equipments (UEs) and storing the public keys in the Ethereum Blockchain. The media is encrypted e2e using the Secure Real Time Protocol (SRTP) protocol with a variety of session key distribution mechanisms. Results showed that the solution implementation has minimal impact on the existing IMS network, and the secure call setup time between two terminals is negligible compared to the original VoLTE setup time.