Imperfect secrecy in wiretap channel II

In a point-to-point communication system which consists of a sender s, a receiver t and a set of noiseless channels, the senders wants to transmit a private message to the receiver t through the channels which may be eavesdropped by a wiretapper. The wiretapper can access any one but not more than one set of channels, which is referred to as a wiretap set. It is assumed that from each wiretap set, the wiretapper can obtain some partial information about the private message which is measured by the wiretapper´s equivocation. The security strategy is to encode the message with some random key. Under these settings, we define an achievable rate tuple in terms of the message, the key and the wiretapper´s equivocation, and prove a tight rate region of the rate tuples.