21 research outputs found
Secret Key Generation from Correlated Sources and Secure Link
In this paper, we study the problem of secret key generation from both
correlated sources and a secure channel. We obtain the optimal secret key rate
in this problem and show that the optimal scheme is to conduct secret key
generation and key distribution jointly, where every bit in the secret channel
will yield more than one bit of secret key rate. This joint scheme is better
than the separation-based scheme, where the secure channel is used for key
distribution, and as a result, every bit in the secure channel can only provide
one bit of secret key rate.Comment: 5 pages, 1 figur
Previous Messages Provide the Key to Achieve Shannon Capacity in a Wiretap Channel
We consider a wiretap channel and use previously transmitted messages to
generate a secret key which increases the secrecy capacity. This can be
bootstrapped to increase the secrecy capacity to the Shannon capacity without
using any feedback or extra channel while retaining the strong secrecy of the
wiretap channel.Comment: Accepted for IEEE International Conference on Communications Workshop
(ICC) 2013, Budapest, Hungary. arXiv admin note: text overlap with
arXiv:1404.570
Opportunistic Secrecy with a Strict Delay Constraint
We investigate the delay limited secrecy capacity of the flat fading channel
under two different assumptions on the available transmitter channel state
information (CSI). The first scenario assumes perfect prior knowledge of both
the main and eavesdropper channel gains. Here, upper and lower bounds on the
delay limited secrecy capacity are derived, and shown to be tight in the high
signal-to-noise ratio (SNR) regime. In the second scenario, only the main
channel CSI is assumed to be available at the transmitter where, remarkably, we
establish the achievability of a non-zero delay-limited secure rate, for a wide
class of channel distributions, with a high probability. In the two cases, our
achievability arguments are based on a novel two-stage key-sharing approach
that overcomes the secrecy outage phenomenon observed in earlier works.Comment: Submitted to IEEE Transactions on Information Theor