Private Key and Group Key Generation Using Correlated Sources and Wiretap Broadcast Channel in Presence of One-Way Public Communication

Encryption with shared key is one of the methods to ensure secure communication. To meet the requirements of keys, this paper investigates the problem of generating private key (PK) and group key (GK) using correlated sources and discrete memoryless wiretap broadcast channel (DM-WBC), in presence of one-way public communication. In the model considered, one transmitter (Alice) and three receivers (Bob, Carol and Eve) are connected via a DM-WBC, and a one-way communication over a public noiseless channel, initiated by Alice, is available. Alice and Bob wish to share a PK that is concealed from Carol and Eve, and they also want to generate a GK with Carol that needs to keep secret from Eve. Under this model, the key capacity regions of PK and GK are established by designing joint source-channel coding schemes to achieve these regions. In PK-generation, the considered model can be viewed as a one receiver two-eavesdropper model, and Alice and Bob have access to correlated source sequences. In GK-generation, the considered model can be viewed as a two-receiver one eavesdropper model, and the three legitimate parties (Alice, Bob and Carol) all have the source observations. Furthermore, the security performance of the generated keys are analyzed by analyzing key leakage rate of each key.