Low-power Secret-key Agreement over OFDM
This provides a practical solution for secure communication in wireless systems, but it is incremental as it builds on existing low-power and OFDM frameworks.
The paper tackles secret-key agreement over OFDM links at low power in the presence of an eavesdropper, showing that using LDPC codes for information reconciliation yields a practical approach with feasibility confirmed by numerical results.
Information-theoretic secret-key agreement is perhaps the most practically feasible mechanism that provides unconditional security at the physical layer to date. In this paper, we consider the problem of secret-key agreement by sharing randomness at low power over an orthogonal frequency division multiplexing (OFDM) link, in the presence of an eavesdropper. The low power assumption greatly simplifies the design of the randomness sharing scheme, even in a fading channel scenario. We assess the performance of the proposed system in terms of secrecy key rate and show that a practical approach to key sharing is obtained by using low-density parity check (LDPC) codes for information reconciliation. Numerical results confirm the merits of the proposed approach as a feasible and practical solution. Moreover, the outage formulation allows to implement secret-key agreement even when only statistical knowledge of the eavesdropper channel is available.