Secure multiparty computation has become a focus in the international cryptographic community in recent years.In this paper

we consider how to privately determine whether multiple private data owned by different parties are equal.There is very little literature on this problem at present.To solve this problem

we first propose a new encoding scheme and then use this new encoding scheme together with the threshold ElGamal homomorphic encryption scheme and secret sharing to construct our protocols.We prove that these protocols are private in the semi-honest model by using the well-accepted simulation paradigm.These protocols are also private against collision attack.Efficiency analysis shows that these protocols are efficient.We further construct a protocol that is secure in the malicious model.