Seoul metropolitan government
In this paper, the authors revisit the private over-threshold data aggregation problem, and formally define the problem's security requirements as both data and user privacy goals. To achieve both goals, and to strike a balance between efficiency and functionality, they devise a novel cryptographic construction that comes in two schemes; a fully decentralized construction and its practical but semi-decentralized variant. Both schemes are provably secure in the semi-honest model. They analyze the computational and communication complexities of their construction, and show that it is much more efficient than the existing protocols in the literature.