The Diversity-Multiplexing Tradeoff of Secret-Key Agreement over Multiple-Antenna Channels
Type
ArticleKAUST Department
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) DivisionElectrical Engineering Program
Date
2015-10-20Online Publication Date
2015-10-20Print Publication Date
2016-02Permanent link to this record
http://hdl.handle.net/10754/581764
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We study the problem of secret-key agreement between two legitimate parties, Alice and Bob, in presence an of eavesdropper Eve. There is a public channel with unlimited capacity that is available to the legitimate parties and is also observed by Eve. Our focus is on Rayleigh fading quasi-static channels. The legitimate receiver and the eavesdropper are assumed to have perfect channel knowledge of their channels. We study the system in the high-power regime. First, we define the secret-key diversity gain and the secret-key multiplexing gain. Second, we establish the secret-key diversity multiplexing tradeoff (DMT) under no channel state information (CSI) at the transmitter (CSI-T). The eavesdropper is shown to “steal” only transmit antennas. We show that, likewise the DMT without secrecy constraint, the secret-key DMT is the same either with or without full channel state information at the transmitter. This insensitivity of secret-key DMT toward CSI-T features a fundamental difference between secret-key agreement and the wiretap channel, in which secret DMT depends heavily on CSI-T. Finally, we present several secret-key DMT-achieving schemes in case of full CSI-T. We argue that secret DMT-achieving schemes are also key DMT-achieving. Moreover, we show formally that artificial noise (AN), likewise zero-forcing (ZF), is DMT-achieving. We also show that the public feedback channel improves the outage performance without having any effect on the DMT.Citation
The Diversity-Multiplexing Tradeoff of Secret-Key Agreement over Multiple-Antenna Channels 2015:1 IEEE Transactions on Wireless Communicationsae974a485f413a2113503eed53cd6c53
10.1109/TWC.2015.2492963