The Capacity Region of the Source-Type Model for Secret Key and Private Key Generation

TL;DR

This paper characterizes the capacity region for generating secret and private keys among three terminals with correlated sources, achieving the outer bound through novel coding schemes.

Contribution

It provides a complete characterization of the SK-PK capacity region by designing achievable schemes that meet the outer bound for all cases.

Findings

Achieved the SK-PK capacity region for all cases.

Developed a novel random binning-joint decoding scheme.

Established the capacity region in general.

Abstract

The problem of simultaneously generating a secret key (SK) and private key (PK) pair among three terminals via public discussion is investigated, in which each terminal observes a component of correlated sources. All three terminals are required to generate a common secret key concealed from an eavesdropper that has access to public discussion, while two designated terminals are required to generate an extra private key concealed from both the eavesdropper and the remaining terminal. An outer bound on the SK-PK capacity region was established in [1], and was shown to be achievable for one case. In this paper, achievable schemes are designed to achieve the outer bound for the remaining two cases, and hence the SK-PK capacity region is established in general. The main technique lies in the novel design of a random binning-joint decoding scheme that achieves the existing outer bound.