1 research outputs found
Strong Secrecy in Pairwise Key Agreement over a Generalized Multiple Access Channel
This paper considers the problem of pairwise key agreement without public
communication between three users connected through a generalized multiple
access channel (MAC). While two users control the channel inputs, all three
users observe noisy outputs from the channel and each pair of users wishes to
agree on a secret key hidden from the remaining user. We first develop a
"pre-generated" key-agreement scheme based on secrecy codes for the generalized
MAC, in which the channel is only used to distribute pre-generated secret keys.
We then extend this scheme to include an additional layer of rate-limited
secret-key generation by treating the observed channel outputs as induced
sources. We characterize inner and outer bounds on the strong secret-key
capacity region for both schemes. For a special case of the "pre-generated"
scheme, we obtain an exact characterization. We also illustrate with some
binary examples that exploiting the generalized nature of the generalized MAC
may lead to significantly larger key-agreement rates.Comment: 45 pages, 11 figures, Submitted to the IEEE Transactions on
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