Secret Key Generation Using Compound Sources – Optimal Key-Rates and Communication Costs

Abstract:
Secret key generation describes the problem of generating common randomness between two terminals without giving any information about it to an eavesdropper. In this paper we study secret key generation using compound sources where the terminals have access to correlated components of a compound source and can further use a noiseless public channel for discussion which is open to eavesdroppers. We establish the key-capacity and analyze for different classes of communication protocols the corresponding costs of public communication that are needed for secret key generation using compound sources. Finally, we discuss the case where a wiretapper also observes a correlated component of the source.