Public Key Encryption Schemes Based on Learning with Rounding Problem

Lattice-based cryptography has recently acquired much attention due to many potential advantages: their resistance so far to cryptanalysis by quantum algorithms, their asymptotic efficiency and conceptual simplicity, and the guarantee that their random instances are as hard as the hardness of lattice problems in worst case. In this paper, we propose several public key encryption (PKE) schemes using lattices, including a multi-bit encryption scheme. Compared with the previous schemes, our scheme has smaller key size and cipher text size, without significant increase in calculation.