基於多天線正交多頻分工及位元交錯調變碼系統之實體層安全機制整合設計

Integrated Physical Layer Security Design on MIMO-OFDM Systems and BICM-OFDM Systems

吳之堯(Chih-Yao Wu)

指導教授 ： 葉丙成

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.00236

摘要

無線通訊網路在我們日常生活中日益普遍，但由於無線通訊的廣播性質，非法使用者相當容易便可接收相同訊號並進行竊聽。因此無線通訊網路的私密性和安全性是一個相當重要的課題。近年來如何在實體層上進行安全機制設計吸引了相當多的研究者，其中的一種方法是利用無線通道來汲取秘密資訊。基於無線通道的雙向對稱性，合法使用者可因此擁有相關的隨機參數。在本篇論文中，我們提出兩種不一樣的機制利用無線通道來汲取秘密資訊。第一種提出的機制為P-MOPI，它能在多天線正交多頻分工系統下產生秘密金鑰並且不會犧牲多天線系統的效能。我們利用預編碼矩陣的編號當作一個有效的金鑰產生方法，同時我們旋轉通道量測信號以避免竊聽者得到任何有用的 金鑰資訊。P-MOPI 機制可以讓兩個通訊節點很輕易的產生大量相同的祕密位元作為金鑰使用，所以可以達成安全傳輸並同時擁有多天線系統的效能增益。本篇論文提出的第二個方法為INTERSECT 機制。我們利用秘密的交織器在多天線位元交錯調變碼系統下達成安全通訊，而秘密交織器可由無線通道頻率響應的大小次序來產生。我們使用電腦模擬來檢驗我們提出機制的可行性 ，模擬的結果顯示我們提出的機制擁有優秀的安全性並相當適合用在現行的無線通訊系統上。

關鍵字

實體層安全機制 ； 多天線正交多頻分工系統 ； 位元交錯調變碼系統 ； 秘密金鑰 ； 密碼學 ； 預編碼矩陣編號 ； 秘密交織器 ； 通道量測信號之旋轉

並列摘要

Wireless communication networks become increasingly pervasive in our daily life. But the broadcasting nature makes wireless communication networks vulnerable to eavesdropping. Any receivers receive the transmitted signals are able to analyze the signals. Thus, privacy and security take an important role in wireless communication networks. Recently, providing security on physical-layer draws lots of interests. Physical-layer security can be achieved by secrecy extraction from wireless channel. Based on channel reciprocity, the legitimate nodes share correlated randomness. In this thesis, we propose two different schemes that extract secrecy from wireless channel. The first one is called P-MOPI, proposed to generate secret keys without sacrifice of MIMO gain for MIMO-OFDM systems. The precoding matrix index (PMI) is utilized as an efficient key generation mechanism and the reference signals are rotated to prevent eavesdropper from learning any secret key information. The P-MOPI scheme easily allows two communicating parties to generate abundant identical secret bits. Both secure communication and the MIMO gain can be guaranteed by using the P-MOPI scheme. The second achievement is the INTERSECT scheme which uses the secret interleaver to ensure confidential transmission for BICM-OFDM system. The order of wireless channel is then utilized as a nature secret source for secret interleaver generation. Computer simulations are done to evaluate the feasibility of our proposed schemes. The results shows the proposed P-MOPI and INTERSECT scheme provides excellent security and are suitable for modern wireless communication systems.

並列關鍵字

Physical-layer Security ； MIMO-OFDM Systems ； BICM Systems ； Secret Key Generation ； Cryptography ； Precoding Matrix Index ； Secret Interleaver ； Rotated Reference Signals

參考文獻

[2] S. Goel and R. Negi, “Guaranteeing secrecy using artificial noise,” , vol. 7, pp. 2180–2189, Jun. 2008.

[3] M. Kobayashi and M. Debbah, “On the secrecy capacity of frequency-selective fading channels : A practical Vandermonde precoding,” in , 2008.

[4] S. Lakshmanan, C.-L. Tsao, R. Sivakumar, and K. Sundaresan, “Securing wireless data networks against eavesdropping using smart antennas,” in , 2008, pp. 19–27.

[5] U. Maurer, “Secret key agreement by public discussion from common information,” , vol. 39, no. 3, pp. 733–742, May 1993.

[6] R. Ahlswede and I. Csisz´ar, “Common randomness in information theory and cryptography, part I: Secret sharing,” , vol. 39, no. 4, pp. 1121–1132, 1993.