Fully-Homomorphic Encryption Based SPIR

The booming of the Internet and its applications, especially, the recent trend in outsourcing databases, fuels the research on symmetrically private information retrieval (SPIR) schemes. In this paper, we propose a fully homomorphic encryption based SPIR scheme in order to further improve the communication cost of SPIR from O((log n)²) to O(log n). Actually, our schemes can be directly used to implement 1-out-of-n oblivious transfer with O(1) sender-side communication complexity.