There are usually two kinds of signals i.e. quantum and classical to process in lots of existing protocols of quantum private comparison (QPC), for they employ quantum technology and classical computation to implement security and comparison, respectively. Classical operations and their information are prone to classical attacks with insufficient security. Therefore, a protocol of quantum gate-based QPC has been proposed without classical operations, but it is only applicable for qubits of computational basis. For its application to diagonal basis, this paper uses quantum gates and GHZ states to propose a new QPC protocol without classical data to process. There being no classical computation could lead to the improvement of security. The presented protocol is not only simple and efficient but also broadening applicable occasions. The analyses indicate its correctness and security.

中文翻译：

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没有经典计算的量子私有比较

现有的许多量子私有比较（QPC）协议通常有量子和经典两种信号来处理，因为它们分别采用量子技术和经典计算来实现安全和比较。经典操作及其信息容易受到安全性不足的经典攻击。因此，提出了一种基于量子门的QPC协议，无需经典运算，但仅适用于计算基础的量子比特。为了将其应用于对角基，本文使用量子门和 GHZ 状态提出了一种新的 QPC 协议，无需处理经典数据。没有经典的计算可以导致安全性的提高。所提出的协议不仅简单高效，而且还拓宽了适用场合。