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.