A note on Wyner's wiretap channel (Corresp.)

Wyner recently introduced the concept of a wiretap channel and showed that by transmitting at a rate less than capacity on the main link it was possible to keep the wiretapper's information about the entire message equal to zero. It is shown that it is possible to send at capacity on the main link and still keep the wiretapper's information equal to zero on many, large, arbitrary portions of the message.