TrustBuilder: A non-repudiation scheme for IoT cloud applications

Abstract

The IoT cloud computing paradigm is emerging for IoT applications. In such a paradigm, how to guarantee non-repudiation service provisioning has attracted research efforts recently. While existing solutions could work for distributed IoT cloud applications, storage, computation, and economic cost is still a practical challenging concern. In this paper, we propose a new, cost-lower non-repudiation scheme for IoT cloud applications. The proposed scheme guarantees that neither the IoT client nor the cloud could repudiate a service enjoyment and provisioning. Specifically, the proposed scheme employs a blockchain to achieve non-repudiation. First, when the cloud provides a service, it encrypts the service, stores a cryptographic hash digest of the encrypted service on the blockchain, and then sends the encrypted service to the IoT client. Second, the IoT client needs to acknowledge the hash digest on the blockchain to obtain the service. Third, the cloud sends the decryption key to the blockchain under the IoT client’s public key to finish a service provisioning. We show that the proposed scheme achieves non-repudiation fairly. We prototyped, evaluated, and open-sourced the proposed scheme. Experimental results confirmed the efficiency of the proposed scheme and the speedup compared with the state-of-the-art solution.