本文選題：物理層安全　切入點：信道相位響應(yīng)　出處：《解放軍信息工程大學(xué)》2014年碩士論文

【摘要】：利用無線信道的唯一性與互易性實現(xiàn)密鑰的分發(fā),是一種基于物理層的安全保障方法。將無線信道特征作為隨機的信號源,對合法用戶的信道進行測量得出相似的密鑰序列,并通過密鑰協(xié)商與保密性增強技術(shù)消除密鑰序列的不一致,最終獲得一致的密鑰�，F(xiàn)有方法存在的問題有:1)較低的量化精度導(dǎo)致密鑰分發(fā)的安全性不足;2)一致化方法需要多輪通信且計算復(fù)雜度高;3)在慢衰落信道條件下,低的密鑰分發(fā)速率限制了系統(tǒng)的實用性。針對上述問題,本文依托國家自然科學(xué)基金項目,對基于信道相位響應(yīng)的物理層密鑰分發(fā)技術(shù)進行研究。首先,針對較低的量化精度導(dǎo)致密鑰分發(fā)安全性不足問題,提出了基于信道相位差異的密鑰分發(fā)方法;然后,針對一致化方法需要多輪通信且計算復(fù)雜度高的問題,提出了信道相位響應(yīng)加密與網(wǎng)格編碼調(diào)制技術(shù)聯(lián)合的密鑰分發(fā)方法;最后,針對慢衰落信道條件下密鑰分發(fā)速率低的問題,提出了一種基于信道相位響應(yīng)估計的協(xié)作密鑰分發(fā)方法。主要研究內(nèi)容包括:1.提出了一種基于信道相位差異的密鑰分發(fā)方法。首先,在單入單出系統(tǒng)模型下,將合法用戶信道與竊聽信道化為相位旋轉(zhuǎn)信道與加性噪聲信道的級聯(lián),計算得出密鑰的各態(tài)歷經(jīng)安全容量;然后,利用合法用戶與竊聽用戶的信道相位差異性進行密鑰提取,可以確保密鑰分發(fā)的安全性。同時,將信道相位的提取精度轉(zhuǎn)換為密鑰長度,可以通過提高提取精度來增大密鑰空間;最后,利用連續(xù)密鑰分發(fā)策略逼近密鑰容量,并以二進制信源為例說明本方法。仿真結(jié)果表明,當(dāng)相位的估計誤差為0.001時,誤碼率會迅速上升為0.5。2.提出了一種信道相位響應(yīng)加密與網(wǎng)格編碼調(diào)制技術(shù)聯(lián)合的密鑰分發(fā)方法。首先,對隨機生成的密鑰序列進行網(wǎng)格編碼調(diào)制得到帶有冗余的密鑰信息,發(fā)送方利用對信道相位響應(yīng)量化后的保密序列對密鑰信息進行隱藏得到校驗信息,并公開發(fā)送給接收方;然后,接收方利用消除信道相位響應(yīng)的量化噪聲后的保密序列將校驗信息中的密鑰信息恢復(fù)出來,同時利用密鑰信息的冗余糾正兩端保密序列不一致導(dǎo)致的恢復(fù)誤差的影響,最終獲得一致的密鑰。仿真結(jié)果表明,在誤比特率為10-4時,該方法比現(xiàn)有方法有將近5dB的增益。3.提出了一種基于信道相位響應(yīng)估計的協(xié)作密鑰分發(fā)方法。首先,構(gòu)造了協(xié)作中繼密鑰分發(fā)模型;然后,密鑰節(jié)點與中繼節(jié)點相互發(fā)送初始相位為零的單音信號進行信道相位估計,明確考慮了最大似然估計方法對密鑰提取的影響,并對估計后的信息進行等間隔量化;最后,中繼節(jié)點將量化后的信息發(fā)送給密鑰節(jié)點,密鑰節(jié)點之間采用基于網(wǎng)格編碼調(diào)制的密鑰協(xié)商方法獲得一致的密鑰。仿真結(jié)果表明,隨著中繼個數(shù)的增加,密鑰生成速率呈線性增加,并且當(dāng)中繼個數(shù)為5時,密鑰生成速率達到1500bits/s。
[Abstract]:Using the uniqueness and reciprocity of wireless channel to realize key distribution is a physical layer based security method.The wireless channel feature is used as a random signal source to measure the channel of the legitimate user to obtain the similar key sequence, and to eliminate the inconsistency of the key sequence by key agreement and privacy enhancement technique, and finally to obtain the consistent key.The existing methods have the following problems: the low quantization accuracy of 1) leads to the lack of security of key distribution. The consistency method requires multiple rounds of communication and high computational complexity in slow fading channels.The low key distribution rate limits the practicability of the system.In view of the above problems, this paper studies the physical layer key distribution technology based on channel phase response based on the National Natural Science Foundation project.Firstly, a key distribution method based on channel phase difference is proposed to solve the problem that low quantization precision leads to insufficient security of key distribution.A key distribution method based on the combination of channel phase response encryption and trellis coding modulation is proposed. Finally, the problem of low key distribution rate in slow fading channels is discussed.A cooperative key distribution method based on channel phase response estimation is proposed.The main research contents include: 1.A key distribution method based on channel phase difference is proposed.First of all, under the model of single input and single output system, the legitimate user channel and eavesdropping channel are converted into the cascade of phase rotation channel and additive noise channel, and the security capacity of each state of the key is calculated.The security of key distribution can be ensured by extracting the key by using the channel phase difference between legitimate user and eavesdropping user.At the same time, the precision of the channel phase is converted to the length of the key, which can increase the key space by improving the precision of the extraction. Finally, a continuous key distribution strategy is used to approximate the key capacity, and the binary source is taken as an example to illustrate the method.The simulation results show that when the phase estimation error is 0.001, the bit error rate will rise rapidly to 0.5.2.In this paper, a key distribution method based on channel phase response encryption and trellis coding modulation is proposed.Firstly, the key information with redundancy is obtained by trellis coding modulation of the randomly generated key sequence, and the key information is hidden by the secret sequence after quantization of the channel phase response.The receiver then recovers the key information in the check information using a secret sequence of quantized noise that eliminates the phase response of the channel.At the same time, the redundancy of the key information is used to correct the effect of the restoration error caused by the inconsistency between the two ends of the secret sequence, and finally the consistent key is obtained.The simulation results show that when the bit error rate is 10-4, the gain of this method is close to that of 5dB. 3.A cooperative key distribution method based on channel phase response estimation is proposed.First of all, a cooperative relay key distribution model is constructed, and then the channel phase estimation of single tone signal with zero initial phase is carried out by the key node and relay node, and the influence of the maximum likelihood estimation method on the key extraction is explicitly considered.The estimated information is quantized at equal intervals. Finally, the relaying node sends the quantized information to the key node, and the key agreement method based on trellis coding modulation is used to obtain the consistent key.Simulation results show that the key generation rate increases linearly with the number of relays, and when the number of relays is 5, the key generation rate reaches 1500 bits / s.
【學(xué)位授予單位】：解放軍信息工程大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN918.4

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相關(guān)期刊論文 前1條

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本文編號：1719132