Quantum Private Comparison of Equality Based on Five-Particle Cluster State

A protocol for quantum private comparison of equality(QPCE) is proposed based on five-particle cluster state with the help of a semi-honest third party(TP). In our protocol, TP is allowed to misbehave on its own but can not conspire with either of two parties. Compared with most two-user QPCE protocols, our protocol not only can compare two groups of private information(each group has two users) in one execution, but also compare just two private information. Compared with the multi-user QPCE protocol proposed, our protocol is safer with more reasonable assumptions of TP. The qubit efficiency is computed and analyzed. Our protocol can also be generalized to the case of 2N participants with one TP. The 2N-participant protocol can compare two groups(each group has N private information)in one execution or just N private information.

Development of and prospects for the biological weapons convention

Biological weapons are used in wars to wound or kill people or animals and destroy crops with pathogenic microorganisms such as bacteria and viruses,as well as toxins and other biologically active substances.These are highly infectious,easily communicable,widely destructive,long-acting,and difficult to prevent and treat.Thus,a major challenge for the international community is preventing the spread of biological weapons throughout the world.The Biological Weapons Convention(BWC)is a multilateral treaty that clearly prohibits the development,production,stockpiling,acquisition and preservation of biological and toxic weapons,as well as the design and delivery of biological warfare agents,except for the purpose of prevention,protection and other peaceful uses.The BWC is,to a certain extent,binding on countries capable of manufacturing biological weapons,and has become a powerful tool enabling the international community to jointly deal with the threats posed by biological weapons.However,its effectiveness has been reduced by the lack of a corresponding verification mechanism.With the rapid development of biotechnology,global biosecurity is faced with new and highly uncertain challenges and threats,which requires the member countries of the BWC to cooperate with,promote,and supervise each other in making constant improvements to the BWC in an effort to maintain global peace and stable development.

Quantum Private Comparison via Cavity QED

The first quantum private comparison(QPC) protocol via cavity quantum electrodynamics(QED) is proposed in this paper by making full use of the evolution law of atom via cavity QED, where the third party(TP) is allowed to misbehave on his own but cannot conspire with either of the two users. The proposed protocol adopts two-atom product states rather than entangled states as the initial quantum resource, and only needs single-atom measurements for two users. Both the unitary operations and the quantum entanglement swapping operation are not necessary for the proposed protocol. The proposed protocol can compare the equality of one bit from each user in each round comparison with one two-atom product state. The proposed protocol can resist both the outside attack and the participant attack.Particularly, it can prevent TP from knowing two users' secrets. Furthermore, the qubit efficiency of the proposed protocol is as high as 50%.