IoT Data Privacy Protection Scheme based on Blockchain

Abstract

This article introduces the blockchain technology and proposes a blockchain-based IoT sensor data privacy protection scheme from the anonymisation of user identity, the protection of private data and the procedure that allows third parties to use encrypted sensor data. The sensor and the gateway establish a connection after authentication and key negotiation, and the sensor periodically uploads the sampled data and hash-based message authentication code (HMAC) to the gateway. After the gateway verifies the HMAC code of the sensor data, it encrypts the sensor data, constructs a blockchain transaction and submits it to the blockchain node. Blockchain nodes cache transactions and periodically generate blocks to confirm that the transactions are on the chain. After the gateway constructs an authorised transaction and submits it to the blockchain node for confirmation, the designated decentralised application (DApp) obtains the permission and related keys to access the designated sensor managed by the gateway. Finally, the DApp queries the local blockchain node for the specified sensor data and decrypts the results. Experiments have proven through in-depth discussions on sensor synthesis data, sensor/gateway verification, transaction data encryption and transaction signatures that the scheme can be used in IoT systems.