  In this paper we propose a feedback scheme for transmitting secret messages
between two legitimate parties, over an eavesdropped communication link.
Relative to Wyner's traditional encoding scheme \cite{wyner1}, our
feedback-based encoding often yields larger rate-equivocation regions and
achievable secrecy rates. More importantly, by exploiting the channel
randomness inherent in the feedback channels, our scheme achieves a strictly
positive secrecy rate even when the eavesdropper's channel is less noisy than
the legitimate receiver's channel. All channels are modeled as binary and
symmetric (BSC). We demonstrate the versatility of our feedback-based encoding
method by using it in three different configurations: the stand-alone
configuration, the mixed configuration (when it combines with Wyner's scheme
\cite{wyner1}), and the reversed configuration. Depending on the channel
conditions, significant improvements over Wyner's secrecy capacity can be
observed in all configurations.
