A distributed privacy-preserving data aggregation scheme for smart grid with fine-grained access control

Smart grid integrates smart meters and modern communication technologies with the traditional electricity grid. It not only improves efficiency in power resource management, but also enhances reliability of the grid. However, the power consumption data may reveal users' privacy, e.g. their living habits, and its authenticity is also important for accurate billing. Although a number of privacy preserving data aggregation schemes for smart grid have been proposed in the literature, most of them still suffer some limitations. For example, a single party is normally required to decrypt the aggregated data and this party could be a single point of failure in the system. Moreover, once the aggregated data is decrypted, no access control is imposed and it is available to the public. In order to address the above problems, we introduce a distributed privacy-preserving data aggregation scheme for smart grid with fine-grained access control. In the proposed scheme, homomorphic encryption is employed to ensure user privacy, digital signature is used to ensure data authenticity, distributed proxy re-encryption is used to achieve fine-grained access control of the aggregated data, and zero-knowledge proof is used to ensure that the proxy servers perform their tasks properly. Security analyses prove that the proposed scheme achieves the desirable security properties. In particular, it does not suffer single point of failure and the aggregated data can only be accessed by the designated recipient. Efficiency analyses also demonstrate that it is practical for real-world applications.