The Role of Channel States in Secret Key Generation
In this paper, the authors investigate secret key generation from channel states. They point out, by means of a packet-delay based attack, that observing its own channel states is not the only way an adversary can learn about the channel states of the legitimate communicating parties. The attack suggests that it is not secure to transmit data via the channel whose states generate secret keys. However, not using the channel at all would result in a waste of bandwidth. Hence, they propose using this channel to transmit the bits needed to reconcile the channel state estimates at the transmitter and the receiver. This is a necessary step in secret key generation that required a separate channel in previous work.