【摘要】：隨著量子信息技術(shù)的快速發(fā)展,量子密鑰分發(fā)技術(shù)逐漸成熟,有望為實(shí)際的信息系統(tǒng)提供安全的密鑰分發(fā)機(jī)制。量子密鑰分發(fā)技術(shù)的獨(dú)特優(yōu)勢(shì)在于它的無條件安全性,雖然其理論安全性已經(jīng)得到證明,但是在實(shí)際的量子密鑰分發(fā)系統(tǒng)中,由于設(shè)備實(shí)現(xiàn)的不完美,無法達(dá)到理論上的理想條件,使竊聽者有機(jī)可乘,導(dǎo)致量子密鑰分發(fā)系統(tǒng)的成碼率降低及量子比特誤碼率升高。因此研究量子密鑰分發(fā)系統(tǒng)的實(shí)際安全性對(duì)成碼率和量子比特誤碼率的改善以及量子通信技術(shù)的發(fā)展應(yīng)用有著重要意義。量子信息雖然相對(duì)于經(jīng)典信息有著巨大的優(yōu)勢(shì),但是在實(shí)際應(yīng)用的過程中,卻遇到了一個(gè)重大障礙——退相干效應(yīng),退相干是由于系統(tǒng)在演化的過程中與環(huán)境不可避免地相互作用導(dǎo)致的。在量子密鑰分發(fā)系統(tǒng)中,即使沒有攻擊者存在,因?yàn)橥讼喔尚?yīng)的影響,也會(huì)使成碼率降低,量子比特誤碼率升高。因此如何抑制退相干已經(jīng)成為現(xiàn)階段一個(gè)越來越重要的研究課題。本文主要研究量子密鑰分發(fā)系統(tǒng)的實(shí)際安全性及退相干抑制兩個(gè)方面。本文完成的工作包括:首先,介紹量子密鑰分發(fā)系統(tǒng)安全性和退相干抑制研究的意義及現(xiàn)狀,給出了量子保密通信相關(guān)的背景知識(shí),包括量子力學(xué)的基本知識(shí)、兩個(gè)典型的量子密鑰分發(fā)協(xié)議BB84協(xié)議和B92協(xié)議、量子密鑰分發(fā)系統(tǒng)中單光子信號(hào)制備及單光子探測(cè)器等關(guān)鍵技術(shù)。然后,詳細(xì)研究了幾種典型的邊信道攻擊方法,包括PNS攻擊、相位重映射攻擊、探測(cè)致盲攻擊等等,同時(shí)討論了對(duì)應(yīng)的抗攻擊措施。對(duì)基于B92協(xié)議的量子密鑰分發(fā)系統(tǒng)實(shí)驗(yàn)平臺(tái)進(jìn)行分析,發(fā)現(xiàn)其在隨機(jī)數(shù)生成、弱相干光源、偏振控制、單光子探測(cè)等方面存在的安全漏洞,并給出解決方案。其次,詳細(xì)介紹弱測(cè)量-恢復(fù)的實(shí)現(xiàn)原理,將該方法用于抑制幅值阻尼信道噪聲,通過公式推導(dǎo)及MATLAB仿真,驗(yàn)證了該方法抑制幅值阻尼信道噪聲時(shí),理想情況下可以使量子態(tài)無限趨近于初始量子態(tài),達(dá)到完全抑制退相干的效果。最后,將弱測(cè)量-恢復(fù)方法應(yīng)用于抑制相位阻尼信道噪聲和退極化信道噪聲,通過嚴(yán)格的公式推導(dǎo),詳細(xì)討論該方法抑制相位阻尼信道噪聲時(shí)對(duì)量子保真度的影響,分別設(shè)置弱測(cè)量強(qiáng)度、恢復(fù)測(cè)量強(qiáng)度及量子信道的退相干程度這三個(gè)參數(shù),用MATLAB進(jìn)行仿真,驗(yàn)證理論推導(dǎo)的正確性。本文對(duì)量子密鑰分發(fā)系統(tǒng)的安全性分析及退相干抑制研究具有理論意義。本文仍需進(jìn)一步研究和完善的地方有以下幾個(gè)方面:(1)針對(duì)量子密鑰分發(fā)實(shí)驗(yàn)平臺(tái)存在的安全漏洞,不斷對(duì)其進(jìn)行改進(jìn)與完善,從而提高成碼率,降低量子比特誤碼率。(2)研究弱測(cè)量-恢復(fù)方法進(jìn)行退相干抑制時(shí)對(duì)量子密鑰分發(fā)系統(tǒng)的成碼率及量子比特誤碼率的影響。
[Abstract]:With the rapid development of quantum information technology, quantum key distribution technology is gradually mature, which is expected to provide a secure key distribution mechanism for practical information systems. The unique advantage of quantum key distribution technology lies in its unconditional security. Although its theoretical security has been proved, in the actual quantum key distribution system, due to the imperfect implementation of the device, It can not reach the ideal condition in theory, which makes the eavesdroppers take advantage of it, which leads to the decrease of the bit rate and the increase of the bit error rate of the quantum key distribution system. Therefore, it is of great significance to study the practical security of quantum key distribution system for the improvement of bit rate and bit error rate and the development and application of quantum communication technology. Although quantum information has a great advantage over classical information, it has encountered a great obstacle in practical application, namely decoherence effect. Decoherence is due to the inevitable interaction between the system and the environment during the evolution process. In the quantum key distribution system, even if no attacker exists, because of the effect of decoherence, the rate of bit formation will decrease and the bit error rate of quantum bit will increase. Therefore, how to suppress decoherence has become an increasingly important research topic. This paper focuses on the practical security and decoherence suppression of quantum key distribution systems. The work accomplished in this paper includes: firstly, the significance and status of the research on security and decoherence suppression of quantum key distribution system are introduced, and the background knowledge of quantum secret communication, including the basic knowledge of quantum mechanics, is given. Two typical quantum key distribution protocols, BB84 and B92 protocols, single photon signal preparation and single photon detector in quantum key distribution system are proposed. Then, several typical side channel attack methods are studied in detail, including PNS attack, phase remapping attack, blind detection attack and so on, and the corresponding anti-attack measures are also discussed. The experimental platform of quantum key distribution system based on B92 protocol is analyzed, and the security vulnerabilities in random number generation, weak coherent light source, polarization control, single photon detection and so on are found. Secondly, the realization principle of weak measurement and recovery is introduced in detail, and the method is used to suppress the amplitude damping channel noise. Through formula derivation and MATLAB simulation, it is verified that the proposed method can suppress amplitude damping channel noise. Ideally, the quantum state can be infinitely close to the initial quantum state, and the decoherence can be completely suppressed. Finally, the weak measuring-recovery method is applied to suppress the phase damping channel noise and the depolarization channel noise. The influence of this method on the quantum fidelity of the phase damping channel noise suppression is discussed in detail by a strict formula derivation. Three parameters, weak measurement intensity, recovery measurement intensity and decoherence degree of quantum channel, are set up, respectively, and simulated by MATLAB to verify the correctness of the theoretical derivation. This paper is of theoretical significance for security analysis and decoherence suppression of quantum key distribution systems. In this paper, the following aspects are needed to be further studied and improved: (1) aiming at the security holes in the experimental platform of quantum key distribution, we constantly improve and perfect it, so as to improve the code rate. (2) the influence of weak measurement and recovery method on bit formation rate and bit error rate of quantum key distribution system is studied.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：O413;TN918.4

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相關(guān)期刊論文 前1條

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本文編號(hào)：2360898