  In Part I of this two-part paper on confidential communication over wireless
channels, we studied the fundamental security limits of quasi-static fading
channels from the point of view of outage secrecy capacity with perfect and
imperfect channel state information. In Part II, we develop a practical secret
key agreement protocol for Gaussian and quasi-static fading wiretap channels.
The protocol uses a four-step procedure to secure communications: establish
common randomness via an opportunistic transmission, perform message
reconciliation, establish a common key via privacy amplification, and use of
the key. We introduce a new reconciliation procedure that uses multilevel
coding and optimized low density parity check codes which in some cases comes
close to achieving the secrecy capacity limits established in Part I. Finally,
we develop new metrics for assessing average secure key generation rates and
show that our protocol is effective in secure key renewal.
