The semi-quantum key distribution protocol based on the hyperentanglement Bell state of polarization-spatial mode is presented in this paper. This protocol is utilized to share the session keys and construct key hierarchy of security systems in high capacity between the legitimate users securely. Different from the previous protocols, two quantum non-demolition detectors are constructed with cross-Kerr nonlinearities and different phase shifts for distinguishing the Bell states in spatial mode degree of freedom. Meanwhile, this protocol can improve the capacity and efficiency when the legitimate users share the session keys. And the technology of the hyperentanglement purification and hyperentanglement concentration can enhance the robustness and stability of this protocol. At last, this protocol proposed in this paper can withstand several kinds of attacks.
The semi-quantum key distribution protocol based on the hyperentanglement Bell state of polarization-spatial mode is presented in this paper. This protocol is utilized to share the session keys and construct key hierarchy of security systems in high capacity between the legitimate users securely. Different from the previous protocols, two quantum non-demolition detectors are constructed with cross-Kerr nonlinearities and different phase shifts for distinguishing the Bell states in spatial mode degree of freedom. Meanwhile, this protocol can improve the capacity and efficiency when the legitimate users share the session keys. And the technology of the hyperentanglement purification and hyperentanglement concentration can enhance the robustness and stability of this protocol. At last, this protocol proposed in this paper can withstand several kinds of attacks.
Semi-quantum key distribution allows generating a raw key between two communication participants, in which the sender is a quantum participant and the receiver is a classical participant. This article presents an original semi-quantum key distribution protocol based on hyperentangled Bell states. The hyperentangled Bell states can be entangled simultaneously in polarization and spatial degrees of freedom, enhancing channel capacity. According to the characteristics of hyperentangled Bell states, the proposed protocol is more efficient than the protocol based on Bell states. Moreover, the measure–resend attack, the intercept–resend attack, and the entangle–measure attack are analyzed in detail. The security analysis demonstrates that the proposed protocol is secure. In addition, a multi-party semi-quantum key distribution scheme based on hyperentangled Bell states is proposed, which can realize key distribution between one quantum participant and multiple classical participants.
According to the properties of the hyperentangled Bell state and hyper-encoding technology, this paper proposes a high-capacity quantum key distribution protocol with qudits hyper-encoded in polarization and spatial mode degrees of freedom (DOFs). In our protocol, 8 bits of information can be transmitted in one iteration. In contrast, the previous quantum key distribution protocols can only transmit up to 4 or 6 bits in one iteration. Moreover, quantum memory is unnecessary in our protocol. We analyze the relationship between the amount of eavesdropping and the success rate of eavesdropping. With the increase of eavesdropping information, the eavesdropping success probability will decrease sharply. The results show that our protocol is secure. Finally, this protocol is flexible; each qubit has two completely independent DOFs. If one DOF is destroyed, the other can still be used to transmit secure information. The protocol may be useful in the future quantum communication field.
We present two hyperentangled concentration schemes for two-photon systems in a partially hyperentangled Bell state that is simultaneously entangled in polarization, spatial mode and time-bin degrees of freedom (DOFs). The first scheme extracts a maximally hyperentangled Bell state using cross-Kerr nonlinearity, which is discussed in two cases of unknown and known coefficients. We construct quantum nondemolition detectors based on cross-Kerr nonlinearities to implement the polarization and spatial parity check. In this scheme, we only require a small phase shift, as long as it can be distinguished from zero. The second scheme is used to concentrate an initial partially hyperentangled state with only linear optical elements, where coefficients of the initial state are known. Both of the two schemes are feasible with the current experimental technology. Moreover, hyperentanglement DOFs can largely improve the channel capacity of long-distance quantum communication. All of these make our schemes more practical and useful in quantum communication.
This paper proposes a feasible high-capacity tripartite quantum secret sharing protocol based on the two-photon polarization-spatial-mode hyperentangled state. Alice, the secret owner, prepares polarization-spatial-mode hyperentangled photon pairs and distributes them to two agents, Bob and Charlie. Using nonlocal complete Bell state analysis technology assisted by spatial mode entanglement, the two agents can collaborate to distinguish Alice’s Bell state in polarization degree of freedom. Only linear optical elements are needed to construct the agents’ measuring devices, which makes the protocol more feasible in experimental implementation. Compared with the existing quantum secret sharing protocols based on two-photon entanglement, this scheme does not need two-way quantum communication and has high capacity because it can transmit two bits of information with a polarization-spatial-mode hyperentangled photon pair. The proposed quantum secret sharing protocol is secure and reliable due to error correction and privacy amplification technology.
Abstract Quantum dialogue enables two communicators to send their own secret information to each other, but most of the current quantum dialogue protocols have high requirements for the hardware equipment and capabilities of the communicators. In order to reduce the cost of participant, a semi-quantum dialogue scheme based on hyperentangled Bell states is studied in this paper. In our protocol, we combines the idea of semi-quantum key distribution and semi-quantum secure direct communication to realize the exchange of secret information between Alice and Bob, Alice’s information is transmitted to Bob through semi-quantum secure direct communication, while Bob’s message is extracted by Alice through semi-quantum key distribution and one-time pad encryption. This is different from the previous semi-quantum dialogue protocols, and is a new way of thinking. The security analysis shows that our protocol can not only resist the conventional attack strategies, but also has not the drawback of ‘information leakage’ problem. Compared with the existing semi-quantum dialogue protocols, it has some advantages, such as high communication efficiency, saving classical participant’s consumption and security. Although this protocol requires the preparation and analysis of hyperentangled Bell state, which are slightly more complex, it will be shown that all these are achievable by current technology. Our protocol is fully implementable, so it has good application prospects.
We present a complete hyperentangled Bell state analysis protocol for two-photon four-qubit states that are simultaneously entangled in the polarization and time-bin degrees of freedom. The 16 hyperentangled states can be unambiguously distinguished via two steps. In the first step, the polarization entangled state is distinguished deterministically and nondestructively with the help of the cross-Kerr nonlinearity. Then, in the second step, the time-bin state is analyzed with the aid of the polarization entanglement. We also discuss the applications of our protocol for quantum information processing. Compared with hyperentanglement in polarization and spatial-mode degrees of freedom, the polarization and time-bin hyperentangled states provide savings in quantum resources since there is no requirement for two spatial modes for each photon. This is the first complete hyperentangled Bell state analysis scheme for polarization and time-bin hyperentangled states, and it can provide new avenues for high-capacity, long-distance quantum communication.