Abstract
In smart grid, to monitor, predict and control the power consumption in real time, energy usage data have to be periodically collected through publicly accessible communication channels, and are stored in a centralized operation center. However, electricity consumption data may disclose the privacy information of users. Therefore, protecting privacy of users and validity of power usage reports becomes a crucial security issue. In this paper, we propose a security-enhanced data aggregation scheme for smart grid communications based on homomorphic cryptosystem, trapdoor hash functions and homomorphic authenticators. Our scheme can achieve data confidentiality and integrity against the malicious aggregator (e.g. gateway), meaning that the aggregator is not able to access users' private information or corrupt the power consumption reports during the aggregation process. Through extensive analysis, we demonstrate that our scheme can resist potential threats and be proved secure under cryptographic hard assumptions. It has less computational and communication overheads than existing approaches.