Secrecy Capacity Scaling in Large Cooperative Wireless Networks
2017 (English)In: IEEE Transactions on Information Theory, ISSN 0018-9448, E-ISSN 1557-9654, Vol. 63, no 3, 1923-1939 p.Article in journal (Refereed) Published
We investigate large wireless networks subject to security constraints. In contrast to point-to-point, interference-limited communications considered in prior works, we propose active cooperative relaying-based schemes. We consider a network with n(l) legitimate nodes, n(e) eavesdroppers, and path loss exponent alpha >= 2. As long as n(e)(2)(log(n(e))(gamma) = o(n(l)), for some positive gamma, we show that one can obtain unbounded secure aggregate rate. This means zero-cost secure communication, given fixed total power constraint for the entire network. We achieve this result through: 1) the source using Wyner randomized encoder and a serial ( multi-stage) block Markov scheme, to cooperate with the relays and 2) the relays acting as a virtual multi-antenna to apply beamforming against the eavesdroppers. Our simpler parallel ( two-stage) relaying scheme can achieve the same unbounded secure aggregate rate when n(e)(alpha/2+1) (log(n(e))(gamma+delta(alpha/2+1)) = o(n(l)) holds, for some positive gamma, delta. Finally, we study the improvement (to the detriment of legitimate nodes) that the eavesdroppers achieve in terms of the information leakage rate in a large cooperative network in the case of collusion. We show that again the zero-cost secure communication is possible, if n(e)((2+2/alpha)) (log n(e))(gamma) = o(n(l)) holds, for some positive gamma; that is, in the case of collusion slightly fewer eavesdroppers can be tolerated compared with the non-colluding case.
Place, publisher, year, edition, pages
IEEE Press, 2017. Vol. 63, no 3, 1923-1939 p.
Secrecy capacity, scaling laws, cooperative strategies, relaying, large wireless networks, information-theoretic security, colluding eavesdroppers
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-204060DOI: 10.1109/TIT.2016.2645227ISI: 000395822500034ScopusID: 2-s2.0-85013413537OAI: oai:DiVA.org:kth-204060DiVA: diva2:1085719
QC 201703302017-03-302017-03-302017-03-30Bibliographically approved