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oe1(光电查) - 科学论文

34 条数据
?? 中文(中国)
  • Towards polarisation-encoded quantum key distribution in optical fibre networks

    摘要: Quantum key distribution – a process that encodes digital information – often utilises fibre optic technologies for commercial applications. Fibre provides the benefit of a dark channel as well as the convenience of independence of a line-of-sight connection between the sender and receiver. In order to implement quantum key distribution protocols utilising polarisation encoding, the birefringence effects of fibre must be compensated for. Birefringence is caused by manufacturing impurities in the fibre or a change in environmental conditions and results in a rotation of the state of polarisation of light as it is propagated through the fibre. With dynamic environmental conditions, the birefringence effects should be monitored with a test signal at regular time intervals so that the polarisation of each photon can be appropriately compensated to its original state. Orthogonal states are compensated simultaneously, but most protocols, such as BB84 and B92, require non-orthogonal basis sets. Instead of using a compensator for each basis, the presented scheme fixes the polarisation controller onto the plane on the Poincaré that passes through both bases, compensating both non-orthogonal bases simultaneously.

    关键词: cryptography,fibre network,QKD,polarisation encoding,single photon

    更新于2025-09-23 15:23:52

  • Multiparty Quantum Key Agreement Based on Three-Photon Entanglement with Unidirectional Qubit Transmission

    摘要: A multiparty quantum key agreement protocol based on three-photon entangled states is proposed. In this scheme, the quantum channel between all parties is that of a closed loop, in which the qubit transmission is one-way. Each party can obtain the sum of the other parties’ secret key values through the coding rules instead of extracting their private keys. The shared secret key cannot be determined by any subset of all the participants except the universal set and each party makes an equal contribution to the final key. Moreover, the security analysis shows our protocol can resist both outside attacks and inside attacks.

    关键词: Quantum cryptography,Three-photon entanglement,One-way qubit transmission,Quantum key agreement

    更新于2025-09-23 15:23:52

  • Cosine-transform-based chaotic system for image encryption

    摘要: Chaos is known as a natural candidate for cryptography applications owing to its properties such as unpredictability and initial state sensitivity. However, certain chaos-based cryptosystems have been proven to exhibit various security defects because their used chaotic maps do not have complex dynamical behaviors. To address this problem, this paper introduces a cosine-transform-based chaotic system (CTBCS). Using two chaotic maps as seed maps, the CTBCS can produce chaotic maps with complex dynamical behaviors. For illustration, we produce three chaotic maps using the CTBCS and analyze their chaos complexity. Using one of the generated chaotic maps, we further propose an image encryption scheme. The encryption scheme uses high-efficiency scrambling to separate adjacent pixels and employs random order substitution to spread a small change in the plain-image to all pixels of the cipher-image. The performance evaluation demonstrates that the chaotic maps generated by the CTBCS exhibit substantially more complicated chaotic behaviors than the existing ones. The simulation results indicate the reliability of the proposed image encryption scheme. Moreover, the security analysis demonstrates that the proposed image encryption scheme provides a higher level of security than several advanced image encryption schemes.

    关键词: Image privacy,Chaotic system,Image encryption,Cryptography,Security analysis,Chaos-based encryption

    更新于2025-09-23 15:23:52

  • Circular Semi-Quantum Secret Sharing Using Single Particles

    摘要: Semi-quantum secret sharing (SQSS) is an important branch of semi-quantum cryptography, and di?ers from quantum secret sharing (QSS) in that not all parties are required to possess quantum capabilities. All previous SQSS protocols have three common features: (i) they adopt product states or entangled states as initial quantum resource; (ii) the particles prepared by quantum party are transmitted in a tree-type way; and (iii) they require the classical parties to possess the measurement capability. In this paper, two circular SQSS protocols with single particles are suggested, where the ?rst one requires the classical parties to possess the measurement capability while the second one does not have this requirement. Compared with the previous SQSS protocols, the proposed SQSS protocols have some distinct features: (i) they adopt single particles rather than product states or entangled states as initial quantum resource; (ii) the particles prepared by quantum party are transmitted in a circular way; and (iii) the second protocol releases the classical parties from the measurement capability. The proposed SQSS protocols are robust against some famous attacks from an eavesdropper, such as the measure-resend attack, the intercept-resend attack and the entangle-measure attack, and are feasible with present quantum technologies in reality.

    关键词: semi-quantum cryptography,semi-quantum secret sharing,measurement capability,circular transmission,single particles

    更新于2025-09-23 15:23:52

  • Memory-assisted quantum key distribution resilient against multiple-excitation effects

    摘要: Memory-assisted measurement-device-independent quantum key distribution (MA-MDI-QKD) has recently been proposed as a technique to improve the rate-versus-distance behavior of QKD systems by using existing, or nearly-achievable, quantum technologies. The promise is that MA-MDI-QKD would require less demanding quantum memories than the ones needed for probabilistic quantum repeaters. Nevertheless, early investigations suggest that, in order to beat the conventional memory-less QKD schemes, the quantum memories used in the MA-MDI-QKD protocols must have high bandwidth-storage products and short interaction times. Among different types of quantum memories, ensemble-based memories offer some of the required specifications, but they typically suffer from multiple excitation effects. To avoid the latter issue, in this paper, we propose two new variants of MA-MDI-QKD both relying on single-photon sources for entangling purposes. One is based on known techniques for entanglement distribution in quantum repeaters. This scheme turns out to offer no advantage even if one uses ideal single-photon sources. By finding the root cause of the problem, we then propose another setup, which can outperform single memory-less setups even if we allow for some imperfections in our single-photon sources. For such a scheme, we compare the key rate for different types of ensemble-based memories and show that certain classes of atomic ensembles can improve the rate-versus-distance behavior.

    关键词: quantum cryptography,quantum networks,quantum key distribution (QKD),quantum memory,single-photon source,quantum communications

    更新于2025-09-23 15:22:29

  • Polarization-based plug-and-play measurement-device-independent quantum key distribution

    摘要: Measurement-device-independent quantum key distribution (MDI-QKD) has received much attention, with the goal of overcoming all of the security loopholes caused by an imperfect detection system. We here propose a plug-and-play MDI-QKD (P&P MDI-QKD) scheme whereby an untrusted relay node, Charlie, owns a laser and sends photons to Alice and Bob. Alice (Bob) modulates the polarization of the incident photons and returns them to Charlie. Charlie uses a modified Bell state analyzer (BSA) to perform Bell state measurements (BSM). In comparison with the original version of MDI-QKD, our scheme exploits a single untrusted laser as the photon source. This makes the signal photons identical and enhances the Hong-Ou-Mandel effect. Second, because of the P&P structure, the setup can automatically eliminate the birefringence influence of the fibers, which makes the setup highly stable. Finally, our modified BSA can identify |Φ?+ and |Φ?? of four Bell states with polarization encoding but not |Ψ?+ and |Ψ??. Based on practical experimental parameters, a simulation showed that the maximum theoretical secure transmission distance could reach more 280 km.

    关键词: Plug-and-play,Measurement-device-independent,Quantum cryptography,Quantum key distribution

    更新于2025-09-23 15:22:29

  • Information hiding scheme based on optical moiré-pixel matrix

    摘要: An information hiding scheme for visual cryptography based on optical moiré-pixel matrix is introduced in this paper. The hiding information is formed by black and white unit square visual moiré-pixels with half of the period of a visual moiré pattern. The moiré-pixels can be accurately determined by designing the parameters in the original gratings. To verify the designed information hiding scheme, we experimentally conduct the sharing gratings to decrypt the information by using ordinary low-cost digital printing. The concealment of the sharing gratings is good to ensure the confidentiality. Both the simulation and experimental results show that the provoked scheme can afford enough security demand, yielding that the moiré-pixel matrix is a flexible platform for cryptographic security.

    关键词: information hiding,visual cryptography,moiré pattern

    更新于2025-09-23 15:22:29

  • [Advances in Intelligent Systems and Computing] Soft Computing for Problem Solving Volume 817 (SocProS 2017, Volume 2) || Design a New Protocol and Compare with BB84 Protocol for Quantum Key Distribution

    摘要: Quantum key distribution is the latest advancement in quantum cryptography. There are several QKD protocols like BB84, B92, Ekert91, COW, SARG04, out of which BB84 is the first protocol developed in 1984. In this paper, we are discussing first about the working of BB84 protocol and then proposing a new protocol which is a variation over BB84 protocol, second the design of simulation setup is discussed, and then we compared the performance of BB84 with the proposed protocol and proved it much better in case of capacity and error estimation. Object-oriented approach is used in the simulation designing for new protocol and BB84 protocol.

    关键词: BB84 simulation,Quantum cryptography,QKD protocols

    更新于2025-09-23 15:21:21

  • Desarrollo de un simulador para el protocolo de criptografía cuántica E91 en un ambiente distribuido

    摘要: The objective of this research work is the development of an application which is capable of simulating the behavior of one of the main developed protocols of quantum cryptography, the protocol E91. In order to achieve this objective, it was essential to carry out an exhaustive investigation of the main concepts, principles and theorems of quantum mechanics; as well as the study of other quantum cryptographic protocols and their development today. With all the collected information, the development of the application begun, starting with the definition of the requirements, then implementing and subsequently testing the application, which allows compiling all the work of analysis and design. The obtained results show the strengths and weaknesses of the application for the secure distribution of a quantum final key. Although this work is primarily the development of the implementation that simulates the behavior of the E91 protocol, it is essentially demonstrative.

    关键词: Quantum mechanics,quantum protocol E91,RMI,quantum cryptography,E91 simulator,distributed programming

    更新于2025-09-23 15:21:01

  • Secure Image Compression Approach based on Fusion of 3D Chaotic Maps and Arithmetic Coding

    摘要: The advances in digital image processing and communications have created a great demand for real–time secure image transmission over the networks. However, the development of effective, fast and secure dependent image compression encryption systems are still a research problem as the intrinsic features of images such as bulk data capacity and high correlation among pixels hinds the use of the traditional joint encryption compression methods. A new approach is suggested in this paper for partial image encryption compression that adopts chaotic 3D cat map to de-correlate relations among pixels in conjunction with an adaptive thresholding technique that is utilized as a lossy compression technique instead of using complex quantization techniques and also as a substitution technique to increase the security of the cipher image. The proposed scheme is based on employing both of lossless compression with encryption on the most significant part of the image after contourlet transform. However the least significant parts are lossy compressed by employing a simple thresholding rule and arithmetic coding to render the image totally unrecognizable. Due to the weakness of 3D cat map to chosen plain text attack, the suggested scheme incorporates a mechanism to generate random key depending on the contents of the image (context key). Several experiments were done on benchmark images to insure the validity of the proposed technique. The compression analysis and security outcomes indicate that the suggested technique is an efficacious and safe for real time image’s applications.

    关键词: Cryptography,Chaotic maps,Joint compression encryption,Contourlet transform,Thresholding,Arithmetic coding

    更新于2025-09-23 15:21:01