Cryptanalysis of secure multiparty quantum summation

Secure multiparty summation plays an important role in the field of secure communication. In this paper, we give a cryptanalysis of a generalized quantum protocol for secure multiparty summation and find a security leak, whereby a dishonest player can steal all the other players' shares and the summation of secrets without being found, which is in conflict with the security requirement for secure multiparty summation. Furthermore, we analyze the reason and present an improved version to deal with the security problem.