Comments on “Enabling Verifiable Privacy-Preserving Multi-Type Data Aggregation in Smart Grids”

Most recently, Zhang et al presented a verifiable data aggregation scheme for smart grids in IEEE Transactions on Dependable and Secure Computing (doi: 10.1109/TDSC.2021.3124546). The authors claim that the privacy of the user's electricity data is preserved, and the control center can check whether the aggregator honestly computes the aggregated ciphertext. However, we indicate that Zhang et al's scheme fails to provide the properties of data privacy and aggregate correctness guarantee. Specifically, by offering concrete attacks, we illustrate that the adversary who has the ability to obtain the decryption key of control center can decrypt any user's ciphertext to get the detailed electricity data, and a misbehaved aggregator will not be detected when it does have some malicious behavior.