A New Security Architecture for Privacy-Preserving Aggregation and Access Control in Smart Grids

We present security architecture for smart grid that supports privacy-preserving, data aggregation and access control. This architecture consists of two parts. In the first part we propose to use an efficient and privacy-preserving aggregation scheme (EPPA), which aggregates real-time data of consumers by Local Gateway. During aggregation the privacy of consumers is protected using Paillier Homomorphic Cryptosystem. The aggregated data will be forwarded by the GW to the Substation/RTU (Remote Terminal Units). The second part uses known access structure with a control mechanism, which gives selective access to data stored in DC and used by different smart grid users. Users can be in the maintenance and monitoring units, policy making centers, utility centers or analysis and prediction centers. This access control scheme uses attribute-based encryption. Users have attributes and keys that are distributed by the Key Distribution Center (KDC). Encrypted data under a set of attributes is stored in the DC by the RTU. Users with the valid attributes can decrypt this information. This access control scheme uses multiple KDCs which make it more robust and resistant against attacks. We theoretically analyze the computation and communication overhead of both schemes and show that these are very low, meaning they are very efficient in our architecture.