关键词: 集合交集, 交集元素关联值, 分布式不经意伪随机函数, ElGamal加密算法, 云辅助

Abstract: The computation of association values for intersection elements is an extension of the privacypreserving set intersection problem, representing a novel challenge in the domain of secure multiparty computation. This paper proposes a scheme for computing the association values of intersection elements securely. Initially, leveraging secret sharing combined with dual cloud servers, we implement a distributed oblivious pseudorandom function (OtdPRF). On this basis, we integrate the concept of oblivious polynomial interpolation with the ElGamal encryption algorithm to achieve a secure computation scheme for the sum of association values of intersection elements between two parties. In the above scheme，homomorphic computation overhead is outsourced to the cloud, thereby reducing computational complexity for participants. Furthermore, we expand the application scenarios based on the scheme for sum of association values of intersection elements, designing and implementing secure determination of threshold relationships and computation of average values of intersection elements. Finally, employing a simulation paradigm, we demonstrate the security of the proposed scheme under a semihonest model and analyze its performance in terms of computation and communication complexity.

Key words: set intersection, association values of intersection elements, distributed oblivious pseudorandom function, ElGamal encryption algorithm, cloudassisted