本文關(guān)鍵詞：量子密鑰分發(fā)后處理關(guān)鍵技術(shù)研究　出處：《哈爾濱工業(yè)大學(xué)》2016年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 量子密鑰分發(fā) 后處理 篩選 誤碼協(xié)商 極化碼 Cascade協(xié)議

【摘要】：密碼技術(shù)是保障信息安全的重要手段,但是現(xiàn)有的密碼技術(shù)通常是計(jì)算安全的。目前唯一被證明是無(wú)條件安全的密碼算法是一次一密(One Time Pad,OTP),但是在實(shí)際應(yīng)用中OTP存在密鑰分發(fā)難的問(wèn)題。量子密鑰分發(fā)(Quantum Key Distribution,QKD)利用量子力學(xué)原理成功解決了密鑰分發(fā)難的問(wèn)題,使OTP算法有了實(shí)際的用武之地。QKD由量子部分與經(jīng)典后處理部分組成。量子部分以量子態(tài)為載體在通信雙方之間分發(fā)部分安全、部分相關(guān)的原始碼,經(jīng)典后處理對(duì)這些原始碼在認(rèn)證的經(jīng)典信道上進(jìn)行篩選、誤碼協(xié)商、私密放大處理,最終得到無(wú)條件安全的密鑰。QKD技術(shù)的目的是為通信參與者提供無(wú)條件安全的密鑰分發(fā),因此提高凈安全密鑰分發(fā)速率是其首要任務(wù)。作為QKD的關(guān)鍵組成部分,QKD后處理理所當(dāng)然要服務(wù)于這一首要任務(wù)。QKD系統(tǒng)由于通信距離、協(xié)議設(shè)計(jì)等因素的不同,輸入到經(jīng)典后處理的原始碼的特點(diǎn)也不盡相同。因此在給定原始碼序列時(shí),如何通過(guò)優(yōu)化QKD后處理各模塊以使凈安全密鑰分發(fā)速率最大化是一個(gè)亟需解決的問(wèn)題。本文的主要研究?jī)?nèi)容和創(chuàng)新性如下:(1)以凈安全碼率最大化為目標(biāo),通過(guò)逐模塊地分析后處理對(duì)原始碼數(shù)據(jù)的處理過(guò)程及其對(duì)凈安全碼率的影響,建立了QKD后處理性能優(yōu)化模型�；谠撃Ｐ�,我們?yōu)楹筇幚砀髂K分別提出了評(píng)價(jià)指標(biāo)。在提出的評(píng)價(jià)指標(biāo)下,我們對(duì)目前的研究熱點(diǎn)——誤碼協(xié)商算法進(jìn)行了性能評(píng)估。此外,在該性能優(yōu)化模型的指導(dǎo)下,我們對(duì)后續(xù)的三個(gè)研究?jī)?nèi)容進(jìn)行了研究。(2)針對(duì)高重復(fù)頻率QKD系統(tǒng)的篩選模塊面臨處理數(shù)據(jù)量大、認(rèn)證密鑰消耗量高的問(wèn)題,提出了一種基于MZRLFL編碼的高壓縮比的篩選算法。提出的算法從分析篩選模塊通信數(shù)據(jù)的特點(diǎn)出發(fā),充分考慮了篩選模塊在處理速率與存儲(chǔ)方面的壓力,具有接近香農(nóng)限的壓縮性能。MZRLFL編碼首先利用修改的游程長(zhǎng)度編碼將二元信源轉(zhuǎn)換為n元信源,再利用可高速編解碼的定長(zhǎng)編碼對(duì)n元信源的消息進(jìn)行編碼。為了彌補(bǔ)定長(zhǎng)編碼壓縮性能的不足,我們通過(guò)尋找最優(yōu)參數(shù)使其壓縮性能達(dá)到最佳。理論分析與實(shí)驗(yàn)結(jié)果表明,提出的算法具有接近香農(nóng)限的性能。為了驗(yàn)證壓縮性能對(duì)認(rèn)證密鑰消耗的影響,將提出的算法應(yīng)用于實(shí)際QKD系統(tǒng)。分析表明,當(dāng)通信距離為1km與25km時(shí),后處理認(rèn)證密鑰消耗量分別減少了26%與15%以上。(3)針對(duì)高篩選碼速率的QKD系統(tǒng)需要高速的誤碼協(xié)商算法,研究了基于極化碼的誤碼協(xié)商算法。我們分析了極化碼在QKD中應(yīng)用模式的安全性及性能,分析表明,極化碼最優(yōu)的兩種應(yīng)用模式的延遲只與譯碼操作有關(guān)。因此我們接著對(duì)SC譯碼算法進(jìn)行了三方面的優(yōu)化以提高譯碼速率,其中前兩個(gè)優(yōu)化主要適于面向硬件實(shí)現(xiàn)的SC譯碼算法,第三個(gè)優(yōu)化主要適于面向軟件實(shí)現(xiàn)的SC譯碼算法。為了給優(yōu)化提供理論支撐,我們分析了SC譯碼算法中似然比計(jì)算的依賴關(guān)系。提出的三方面優(yōu)化為:(i)針對(duì)現(xiàn)有的SC譯碼調(diào)度算法仍很原始這一問(wèn)題,提出了一種高效的SC譯碼調(diào)度算法,與現(xiàn)有算法相比,該算法具有關(guān)鍵路徑延遲與空間復(fù)雜度均為常數(shù)等優(yōu)點(diǎn),能夠降低硬件實(shí)現(xiàn)的存儲(chǔ)資源消耗,并提高硬件實(shí)現(xiàn)的時(shí)鐘頻率,從而提高譯碼速率;(ii)針對(duì)SC譯碼算法譯碼延遲高的問(wèn)題,基于預(yù)先計(jì)算的思想提出了一種低延遲的SC譯碼算法,并詳細(xì)分析了其代價(jià),理論分析表明該算法可以以很低代價(jià)大大降低譯碼延遲;(iii)針對(duì)面向軟件實(shí)現(xiàn)的SC譯碼算法均使用遞歸的方式這一問(wèn)題,提出了一種非遞歸的SC譯碼算法,實(shí)驗(yàn)結(jié)果表明非遞歸的SC譯碼算法的譯碼速度是遞歸的SC譯碼算法的2.2倍至3.3倍。(4)針對(duì)低篩選碼速率的QKD系統(tǒng)需要高協(xié)商效率的誤碼協(xié)商算法,提出了一種高協(xié)商效率的誤碼協(xié)商算法。鑒于在已有的誤碼協(xié)商算法中,Cascade類算法在協(xié)商效率方面通常具有最好的性能。秉著盡可能利用已有信息推斷分組的奇偶性,避免無(wú)謂的信息泄露的思想,我們從兩方面優(yōu)化了Cascade類算法。首先,我們證明了Cascade類算法利用回溯糾錯(cuò)技術(shù)對(duì)每個(gè)分組進(jìn)行糾錯(cuò)時(shí)總是糾正偶數(shù)個(gè)錯(cuò)誤,利用該性質(zhì)我們可以推斷第i輪(i大于等于2)的最后一個(gè)分組的奇偶校驗(yàn)碼總是相同,無(wú)需進(jìn)行交互比對(duì)。其次,我們發(fā)現(xiàn),在Cascade類算法回溯糾錯(cuò)時(shí),對(duì)于長(zhǎng)度為2的分組可以不執(zhí)行BINARY過(guò)程而直接完成糾錯(cuò)。這兩方面的優(yōu)化減少了Cascade類算法糾錯(cuò)過(guò)程中的信息泄露量,提高了協(xié)商效率。
[Abstract]:Cryptography is an important means to ensure information security, but the existing cryptography is usually secure. At present, the only proven cryptographic algorithm is unconditionally secure is a secret (One Time, Pad, OTP), but in the actual application of OTP are key points of attack. Quantum key distribution (Quantum Key, Distribution, QKD) by using the principle of quantum mechanics has successfully solved the key problems in the OTP algorithm, with the actual use. The QKD is composed of the quantum part and the classical post-processing section. The quantum part distributes some secure and partially related codes between the two sides with the quantum state as the carrier. After classical post-processing, the original codes are screened, the error codes are negotiated, and the private amplification processes are processed. Finally, the unconditionally secure key is obtained. The purpose of QKD technology is to provide unconditionally secure key distribution for communication participants, so improving the net secure key distribution rate is its primary task. As a key component of QKD, QKD post processing is of course to serve this primary task. Because of the difference of communication distance, protocol design and other factors, the characteristics of the original code input to the classic post processing in QKD system are different. Therefore, it is an urgent problem how to maximize the net security key distribution rate by optimizing the QKD after the optimization of the original code sequence. The main contents and innovations of this paper are as follows: (1) with the goal of maximizing net security rate, we analyze the process of post processing on the raw code data and its influence on net security bit rate by modular analysis, and establish a QKD post-processing performance optimization model. Based on this model, we put forward evaluation indexes for each module respectively. Under the proposed evaluation index, we evaluate the performance of the current research focus, the error code negotiation algorithm. In addition, under the guidance of the performance optimization model, we have studied the following three research contents. (2) aiming at the problem of high data volume and high consumption of authentication key for screening module of high repetition rate QKD system, a new algorithm based on MZRLFL coding for high compression ratio is proposed. The proposed algorithm takes account of the characteristics of the communication data of the screening module, and fully considers the pressure of the screening module in terms of processing speed and storage, and has the compression performance approaching the Shannon limit. MZRLFL coding first uses the modified run length encoding to transform the two element source into the N source, then encodes the message of N meta source by using the fixed length encoding with high speed encoding and decoding. In order to make up for the shortage of the compression performance of the fixed length coding, we make the best compression performance by finding the optimal parameters. Theoretical analysis and experimental results show that the proposed algorithm has the performance of close to the Shannon limit. In order to verify the effect of compression performance on authentication key consumption, the proposed algorithm is applied to the actual QKD system. The analysis shows that when the communication distance is 1km and 25km, the post processing authentication key consumption is reduced by 26% and more than 15%, respectively. (3) for QKD system with high filter rate, a high speed error negotiation algorithm is needed, and the error code negotiation algorithm based on polarization code is studied. We analyze the security and performance of the application mode of polarization code in QKD. The analysis shows that the delay of the two best application modes is only related to the decoding operation. Therefore, we have optimized the SC decoding algorithm in three ways to improve the decoding rate. The first two optimizations are mainly suitable for the SC decoding algorithm for hardware implementation, and the third optimization is mainly suitable for the SC decoding algorithm for software implementation. In order to provide theoretical support for optimization, we analyze the dependence of the likelihood ratio calculation in the SC decoding algorithm. Three optimization is put forward: (I) SC for decoding the existing scheduling algorithm is still very primitive this problem, proposes a SC decoding efficient scheduling algorithm, compared with the existing algorithms, this algorithm has the critical path delay and space complexity are constants and other advantages, can reduce storage resources low hardware implementation consumption, and improve the clock frequency of the hardware implementation, so as to improve the decoding rate; (II) for SC decoding algorithm, the decoding delay high, pre computation proposed a low delay based on the SC algorithm, and a detailed analysis of the price, theoretical analysis shows that this algorithm can greatly reduce the cost of a very low the decoding delay; (III) the problem for SC decoding algorithm oriented software using recursive way, proposes a non recursive SC algorithm, the experimental results show that the decoding speed of decoding SC non recursive algorithm is recursive 2.2 to 3.3 times the SC decoding algorithm returned. (4) a high negotiation efficiency error negotiation algorithm is proposed for QKD system with low filter rate, which requires high negotiation efficiency. In view of the existing error negotiation algorithms, the Cascade class algorithm usually has the best performance in terms of negotiation efficiency. We optimize the Cascade class algorithm from two aspects, in order to use the existing information as far as possible to deduce the parity of the packet, and to avoid the meaningless information disclosure. First, we show that the Cascade algorithm with backtracking always correct even a mistake correcting technique for error correction for each packet, we can infer the properties of the I wheel (I is greater than or equal to 2) parity check code of the last packet is always the same, without the need for mutual comparison. Secondly, we found that in the Cascade class algorithm backtracking error correction, for the length of 2 of the packet can not perform the BINARY process and directly complete the error correction. The two aspects of the optimization reduce the information leakage in the Cascade class algorithm, and improve the negotiation efficiency.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：TN918.4;O413

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相關(guān)期刊論文 前1條

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本文編號(hào)：1343814