Security improvements for privacy-preserving quantum multiparty computation based on circular structure

Deng et al. (J Inf Secur Appl 47:120-124, 2019) recently proposed a quantum multiparty collaborative computation protocol that claims that the private information of trustful participants is secure against the distrustful ones. They also analyzed the security of their model against a malicious user and claimed that it is secure. However, our work shows that Deng et al.'s protocol is insecure against both inside and outside attacks. We suggest a modification to prevent both inside and outside attacks from getting any useful information. Also, the proposed modified version allows all participated users to compute the final statistics instead of just one user.