In a recent paper [Int. J. Quantum Inf. 17 (2019) 1950026], the authors discussed the shortcomings in the security of a quantum private comparison protocol that we previously proposed [Int. J. Quantum Inf. 15 (2017) 1750014]. They also proposed a new protocol aimed to avoid these problems. Here, we analyze the information leaked in their protocol, and find that it is even less secure than our protocol in certain cases. We further propose an improved version which has the following advantages: (1) no entanglement needed, (2) quantum memory is no longer required, and (3) less information leaked. Therefore, better security and great feasibility are both achieved.

中文翻译：

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Wu-Cai-Wu-Zhang的量子私有比较协议的密码分析和改进

在最近的一篇论文中 [Int. J.量子信息。17 (2019) 1950026]，作者讨论了我们之前提出的量子私有比较协议的安全性缺陷 [Int. J.量子信息。15（2017）1750014]。他们还提出了一个旨在避免这些问题的新协议。在这里，我们分析了他们协议中泄露的信息，发现在某些情况下它甚至不如我们的协议安全。我们进一步提出了一个改进的版本，它具有以下优点：（1）不需要纠缠，（2）不再需要量子存储器，以及（3）信息泄露更少。因此，既获得了更好的安全性，又获得了极大的可行性。