000			04098nam a22002537a 4500
008			210223b2009 a|||f mb|| 00| 0 eng d
040			_aEG-CaNU _cEG-CaNU
041	0		_aeng _beng
082			_a005
100	0		_aAly Mahmoud Mohamed AbdelRahman ElGamal
245	1		_aInformation Theoretic Secrecy in Two-Way Channels / _cAly Mahmoud Mohamed AbdelRahman ElGamal
260			_c2009
300			_a72 p. _bill. _c21 cm.
500			_3Supervisor: Moustafa Youssef
502			_aThesis (M.A.)—Nile University, Egypt, 2009 .
504			_a"Includes bibliographical references"
505	0		_aContents: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Overview of Related Work . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 Contribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.3 Thesis Organization . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2. The One-Way Wire-Tap Channel . . . . . . . . . . . . . . . . . . . . . . 7 2.1 System Model and Notation . . . . . . . . . . . . . . . . . . . . . . 7 2.1.1 Channel Model . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.2 The Discrete Memoryless Wire-Tap Channel . . . . . . . . . . . . . 10 2.3 The Gaussian Wire-Tap Channel . . . . . . . . . . . . . . . . . . . 13 3. Achievable Secrecy Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.1 System Model and Notation . . . . . . . . . . . . . . . . . . . . . . 15 3.2 Channel Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.3 Discrete Memoryless Channels . . . . . . . . . . . . . . . . . . . . 18 3.4 The Gaussian Channel . . . . . . . . . . . . . . . . . . . . . . . . . 24 v 4. A Practical Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 4.1 System Model and Notation . . . . . . . . . . . . . . . . . . . . . . 30 4.2 Analytical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4.2.1 One-Way Communication with Feedback . . . . . . . . . . . 32 4.2.2 Two-Way Communication with Randomized Scheduling . . 33 4.3 Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4.4 Experimental Results . . . . . . . . . . . . . . . . . . . . . . . . . 38 5. Conclusion and Future Work . . . . . . . . . . . . . . . . . . . . . . . . . 43 Bibliography . . . . . . . . . . . . .
520	3		_aAbstract: This thesis is concerned with the study of realizing reliable and secure twoway communication in the presence of a passive eavesdropper (Eve). Our approach achieves perfect information theoretic secrecy via a novel scheme that employs both random binning and channel prefixing. The key idea is to let both users jointly optimize the prefix channel distributions, such that their new channel conditions are favorable compared to Eve’s channel. Random binning is then used to exploit the secrecy advantage offered by the cascade channel. An achievable rate region for the general discrete memoryless channel is provided, and a corollary for the modulo-two channel is given. Next, a practical setting, where the nodes have half-duplex antennas, is explored for the modulo-two and Gaussian channels. In the Gaussian setting, the channel coefficients are based on a free space path loss model. In this setting, we use a randomized scheduling and power allocation scheme, where we allow Alice and Bob to send symbols at random time instants. While Alice will be able to determine the symbols transmitted by Bob, Eve will suffer from ambiguity regarding the source of any particular symbol. This desirable ambiguity is enhanced, in our approach, by randomizing the transmit power level. Finally, we interpret our results in an experimental setup using IEEE 802.15.4-enabled sensor boards, and show that a Wireless Body Area Network (WBAN) is a natural application to our approach.
546			_aText in English, abstracts in English.
650		4	_aWireless Technologies _9327
655		7	_2NULIB _aDissertation, Academic _9187
690			_aWireless Technologies _9327
942			_2ddc _cTH
999			_c8968 _d8968