Confidential Computation of Corresponding Elements of Set Intersection

Secure multi-party computing is one of the most concerned fields in international cryptography. Besides, the problem of the sum of corresponding elements in the intersection of confidential computing sets is relatively new and has wide application scenarios. By using the addition homomorphism of the Lifted ElGamal threshold cryptosystem, this paper solves two problems related to the corresponding elements of the set intersection, namely, the sum of the associated values of the set intersection elements and the secret judgment of the relationship with the threshold. In the case of known data range, the corresponding secret calculation scheme is designed, in the process of calculation, the correlation value of the intersection elements of the set will not be disclosed, and only the final result is obtained. At the same time, the Lifted ElGamal threshold cryptosystem is used in this paper to resist collusive attacks.