BlAsT: Blockchain-Assisted Key Transparency for Device Authentication

BlAsT is an efficient scheme for achieving certification of data continuity through a history attached to a public blockchain. The scheme guarantees the properties of linearity, non-equivocation, time-stamping and transparency. We discuss the implementation of BlAsT over the Bitcoin and the Ethereum blokchains, provide a techno-economic analysis to evaluate the costs related to blockchain adoption, and numerically assess the performance of the proposed architecture in terms of storage and bandwidth requirements. Results show that the above properties can be guaranteed with a small cryptocurrency payment. The proposed scheme can be used for IoT devices under the assumption that the device is able to either perform blockchain validation or delegate it to a trusted node.