Efficient SMC Protocol Based on Multi-Bit Fully Homomorphic Encryption

Aiming at the problems of large ciphertext size and low efficiency in current secure multi-party computation (SMC) protocol based on fully homomorphic encryption (FHE), paper proves that scheme supports multi-bit proposed by Chen Li et al. satisfies key homomorphism. Based this threshold decryption, a three-round, interactive, leveled, under Common Random String (CRS) model is designed. The proved to be safe semi-honest semi-malicious model. From non-interactive zero-knowledge proof, it can concluded also malicious Its security attributed Decisional Learning With Errors (DLWE) variant problem (some-are-errorless LWE). Compared with existing CRS model, smaller, higher, storage overhead overall performance better than protocol.