关键词: 安全多方计算, 秘密区间与阈值, 同态加密, 门限解密

Abstract:

Secure multi-party computation (SMC) is a research hotspot in cryptography in recent years, and is also a key technology for information security protection. The interval secure multi-party computation problems have important theoretical significance in cryptography. Previous studies rarely involve secret interval, that is, interval is generated by two-party or multi-party, and any one knows nothing about the interval information. The secret interval problems have important practical significance in real life. This paper mainly studies the privacy-preserving determination of secret interval and threshold. Firstly, for the secret interval is generated by two-party, based on Paillier’s homomorphic encryption, this paper proposes a protocol. Secondly, for the secret interval is generated by multi-party, this paper proposes an optimization protocol that uses the coding principle combined with Lifted ElGamal homomorphic encryption. Thirdly, this paper proves the protocols can resist collusion attacks, and proves they are safe by using the simulation paradigm. Finally, many practical application problems can be solved by using the protocols proposed in this paper.

Key words: secure multi-party computation, secret interval and threshold, homomorphic encryption, threshold decryption