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Title: The secrecy capacity of cost-constrained wiretap channels,
In many information-theoretic channel coding prob- lems, adding an input cost constraint to the operational setup amounts to restricting the optimization domain in the capacity formula. This paper shows that, in contrast to common belief, such a simple modification does not hold for the cost-constrained (CC) wiretap channel (WTC). The secrecy-capacity of the discrete memoryless (DM) WTC without cost constraints is described by a single auxiliary random variable. For the CC DM-WTC, however, we show that two auxiliaries are necessary to achieve capacity. Specifically, we first derive the secrecy-capacity formula, proving the direct part via superposition coding. Then, we provide an example of a CC DM-WTC whose secrecy-capacity cannot be achieved using a single auxiliary. This establishes the fundamental role of superposition coding over CC WTCs.  more » « less
Award ID(s):
1740822
NSF-PAR ID:
10298369
Author(s) / Creator(s):
Date Published:
Journal Name:
IEEE transactions on information theory
ISSN:
1557-9654
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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    [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

     
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