Privacy-preserving multi-set operations

We consider several multiset operations in secure two-party setting where Alice and Bob each have a multiset and they want to perform some private computations over the two multisets without revealing and private information which means no one of them would learn more information than what can be deduced from the result. We design some methods to compute union, intersection and element reduction operations effectively and securely and apply these techniques to solve the multiset operations problems in semi-honest setting and consider their extension to the malicious setting.