  Information theoretic secret key agreement is impossible without making
initial assumptions. One type of initial assumption is correlated random
variables that are generated by using a noisy channel that connects the
terminals. Terminals use the correlated random variables and communication over
a reliable public channel to arrive at a shared secret key. Previous channel
models assume that each terminal either controls one input to the channel, or
receives one output variable of the channel. In this paper, we propose a new
channel model of transceivers where each terminal simultaneously controls an
input variable and observes an output variable of the (noisy) channel. We give
upper and lower bounds for the secret key capacity (i.e., highest achievable
key rate) of this transceiver model, and prove the secret key capacity under
the conditions that the public communication is noninteractive and input
variables of the noisy channel are independent.
