卫星通信中量子安全协议的研究

随着信息安全需求的不断增长,卫星通信技术在量子安全通信中的应用备受关注。文中旨在深入探讨卫星通信中的量子安全协议,并强调了技术性和专业性。首先,介绍了量子通信的基础知识,包括量子通信概述和量子密钥分发协议。其次,概述了卫星通信技术及其应用,包括卫星通信系统的概览和卫星通信在安全通信中的应用。然后,详细讨论了卫星通信中的量子安全协议,包括BB84协议在卫星通信中的实现、E91协议及其卫星通信应用以及基于量子密钥分发的卫星通信方案。此外,对量子卫星通信的安全性进行了评估,并提出了卫星通信与地面站协同工作的优化策略。最后,总结了研究的主要发现,并指出了未来的研究方向。

基于格的抗量子认证密钥协商协议研究综述

最近在量子计算研究领域所取得的进展对当前网络安全协议中大多数的安全性依赖传统数论难题的方案构成了严重的潜在安全威胁,作为基础性网络安全协议的认证密钥协商协议首当其冲。由此,抗量子认证密钥协商协议成为了近来的一个研究热点。其中,基于格的后量子密码(Post-Quantum Cryptography)方案由于安全性强、计算效率高,于近年得到了广泛重视且现在正快速发展,有望被列入未来的抗量子密码算法标准。文中重点关注基于格的后量子认证密钥协商协议研究。首先,对抗量子认证密钥协商协议的研究背景进行介绍,并对当前基于格的后量子密码方案安全性设计所基于的主要计算性困难问题进行描述;接着,对现有典型基于格的后量子认证密钥协商协议进行概述,并以两方协议为主要研究对象,对相关方案的基本构造模式和若干当前典型相关协议的性能进行讨论、分析和比较;最后,对当前研究中存在的问题进行总结,并对相关研究的未来发展进行展望。

量子增强安全时间同步协议研究

未来信息网络对于时间同步的精度和可靠性提出了更高的要求,为了验证时间同步协议潜在的安全隐患,文章对精确时间协议(PTP)的报文和延时攻击进行了实验模拟分析。为解决传统加密方式无法抵御时间同步协议延时类攻击的问题,文章将PTP与量子秘钥分发技术相结合,提出了一种面向未来网络同步可靠性需求的量子增强安全同步协议,在加密防控报文攻击的基础上,实现对延时类攻击的检测和预警,触发保护机制。理论分析表明,该协议可主动预防针对时间同步协议的安全攻击,实现时间同步信息的安全传输。

Bidirectional Quantum Secure Direct Communication Network Protocol with Hyperentanglement

We propose a bidirectional quantum secure direct communication(QSDC) network protocol with the hyperentanglment in both the spatial-mode ad the polarization degrees of freedom of photon pairs which can in principle be produced with a beta barium borate crystal.The secret message can be encoded on the photon pairs with unitary operations in these two degrees of freedom independently.Compared with other QSDC network protocols,our QSDC network protocol has a higher capacity as each photon pair can carry 4 bits of information.Also,we discuss the security of our QSDC network protocol and its feasibility with current techniques.

Improved Quantum ＂ Ping-Pong＂ Protocol Based on Extended Three-Particle GHZ State

In order to transmit secure messages, a quantum secure direct communication protocol based on extended three-particle GHZ state was presented, in which the extended three-particle GHZ state was used to detect eavesdroppers. In the security analysis, the method of the entropy theory is introduced, and three detection strategies are compared quantitatively by using the constraint between the information eavesdroppers can obtain and the interference introduced. If the eavesdroppers intend to obtain all inforrmtion, the detection rate of the original ＂Ping-pong＂ protocol is 50% ; the second protocol used two particles of EPR pair as detection particles is also 50%; while the presented protocol is 58%. At last, the security of the proposed protocol is discussed. The analysis results indicate that the protocol in this paper is more secure than the other two.

A Scheme to Share Information via Employing Discrete Algorithm to Quantum States

We propose a protocol for information sharing between two legitimate parties （Bob and Alice） via public-key cryptography. In particular, we specialize the protocol by employing discrete algorithm under mod that maps integers to quantum states via photon rotations. Based on this algorithm, we find that the protocol is secure under various classes of attacks. Specially, owe to the algorithm, the security of the classical privacy contained in the quantum public-key and the corresponding ciphertext is guaranteed. And the protocol is robust against the impersonation attack and the active wiretapping attack by designing particular checking processing, thus the protocol is valid.

Reexamining Security of Improved Multiparty Quantum Secret Splitting and Quantum State Sharing

In a recent letter [H.F. Wang, X. Ji, and S. Zhang, Phys. Lett. A 358 （2006） 11], an improvement of the multiparty quantum secret splitting and quantum state sharing protocol [F.G. Deng, et al., Phys. Lett. A 354 （2006） 190.] was presented. We study the security of the improved protocol and find that two or more dishonest participants may recover the secret from the dealer. Hence we further modify the improved protocol, which make it stand against this kind of attack.

Deterministic quantum communication using the symmetric W state

This study proposes a new coding function for the symmetric W state. Based on the new coding function, a theoretical protocol of deterministic quanama communication （DQC） is proposed. The sender can use the proposed coding function to encode his/her message, and the receiver can perform the imperfect Bell measurement to obtain the sender＇s message. In comparison to the existing DQC protocols that also use the W class state, the proposed protocol is more efficient and also more practical within today＇s technology. Moreover, the security of this protocol is analyzed to show that any eavesdropper will be detected with a very high probability under both the ideal and the noisy quantum channel.

A blind quantum signature protocol using the GHZ states

Recently,some blind quantum signature(BQS) protocols have been proposed.But the previous schemes have security and efficiency problems.Based on the entangled Greenberger-Horne-Zeilinger(GHZ) states,a new weak BQS protocol is proposed.Compared with some existing schemes,our protocol has 100% efficiency.Besides,the protocol is simple and easy to implement.The security of the protocol is guaranteed by the correlation of the GHZ particles held by each participant.In our protocol,the signatory is kept blind from the content of the message.According to the security analysis,the signatory cannot disavowal his/her signature while the signature cannot be forged by others.

Three-step semiquantum secure direct communication protocol

Quantum secure direct communication is the direct communication of secret messages without need for establishing a shared secret key first.In the existing schemes,quantum secure direct communication is possible only when both parties are quantum.In this paper,we construct a three-step semiquantum secure direct communication(SQSDC)protocol based on single photon sources in which the sender Alice is classical.In a semiquantum protocol,a person is termed classical if he(she)can measure,prepare and send quantum states only with the fixed orthogonal quantum basis{|0,|1}.The security of the proposed SQSDC protocol is guaranteed by the complete robustness of semiquantum key distribution protocols and the unconditional security of classical one-time pad encryption.Therefore,the proposed SQSDC protocol is also completely robust.Complete robustness indicates that nonzero information acquired by an eavesdropper Eve on the secret message implies the nonzero probability that the legitimate participants can find errors on the bits tested by this protocol.In the proposed protocol,we suggest a method to check Eves disturbing in the doves returning phase such that Alice does not need to announce publicly any position or their coded bits value after the photons transmission is completed.Moreover,the proposed SQSDC protocol can be implemented with the existing techniques.Compared with many quantum secure direct communication protocols,the proposed SQSDC protocol has two merits:firstly the sender only needs classical capabilities;secondly to check Eves disturbing after the transmission of quantum states,no additional classical information is needed.

Fault tolerant two-step quantum secure direct communication protocol against collective noises

This work proposes two fault tolerant quantum secure direct communication （QSDC） protocols which are robust against two kinds of collective noises： the collective-dephasing noises and the collective-rotation noises, respectively. The two QSDC protocols are constructed from four-qubit DF states which consist of two logical qubits. The receiver simply performs two Bell state measurements （rather than four-qubit joint measurements） to obtain the secret message. The protocols have qubit efficiency twice that of the other corresponding fault tolerant QSDC protocols. Furthermore, the proposed protocols are free from Trojan horse attacks.

Controlled Deterministic Secure Quantum Communication Protocol Based on Three-Particle GHZ States in X-Basis

A controlled deterministic secure quantum communication(CDSQC) protocol is proposed based on threeparticle GHZ state in X-basis.Only X-basis and Z_1Z_2X_3-basis(composed of Z-basis and X-basis) measurement are required,which makes the scheme more convenient than others in practical applications.By distributing a random key between both sides of the communication and performing classical XOR operation,we realize a one-time-pad scheme,therefore our protocol achieves unconditional secure.Because only user with legitimate identity string can decrypt the secret,our protocol can resist man-in-the middle attack.The three-particle GHZ state in X-basis is used as decoy photons to detect eavesdropping.The detection rate reaches 75% per qubit.

Counterfactual Quantum Deterministic Key Distribution

We propose a new counterfactual quantum cryptography protocol concerning about distributing a deterministic key.By adding a controlled blocking operation module to the original protocol [T.G.Noh,Phys.Rev.Lett.103(2009) 230501],the correlation between the polarizations of the two parties,Alice and Bob,is extended,therefore,one can distribute both deterministic keys and random ones using our protocol.We have also given a simple proof of the security of our protocol using the technique we ever applied to the original protocol.Most importantly,our analysis produces a bound tighter than the existing ones.

A Novel Quantum Covert Channel Protocol Based on Any Quantum Secure Direct Communication Scheme

By analyzing the basic properties of unitary transformations used in a quantum secure direct communication (QSDC) protocol, we show the main idea why a covert channel can be established within any QSDC channel which employs unitary transformations to encode information. On the basis of the fact that the unitary transformations used in a QSDC protocol are secret and independent, a novel quantum covert channel protocol is proposed to transfer secret messages with unconditional security. The performance, including the imperceptibility, capacity and security of the proposed protocol are analyzed in detail.