Quantum Private Comparison Using Single Bell State

Quantum private comparison (QPC) can tell us whether two users’ private data are equal or not by quantum technology without disclosing privacy to each other. There are many QPC protocols with diverse procedures and a wide variety of quantum resources. If two forms of quantum states or above are used in a QPC protocol, there will be a need of multiple devices or methods to generate these quantum states, which could bring about some lurking unfavourable effects such as inefficiency and high costs in application. In order to improve the QPC efficiency and reduce costs, a design principle to develop QPC protocols is put forward as a reference in this paper. Also, to take Bell states for example, a QPC protocol with a single Bell state as quantum resource is presented. The protocol is not only simple yet efficient and easy to apply but also of low costs. The analyses show its correctness so it could behave as an alternative way to exercise QPC.