The Secret Key-Private Key Capacity Region for Three Terminals

TL;DR

This paper characterizes the capacity region for secret and private key generation among three terminals with public communication, providing bounds and exact solutions under specific conditions.

Contribution

It introduces inner and outer bounds for the secret-private key capacity region and identifies conditions where these bounds coincide for exact characterization.

Findings

Derived inner and outer bounds for the capacity region.

Identified conditions where bounds coincide, giving exact capacity.

Enhanced understanding of secret and private key generation limits.

Abstract

We consider a model for secrecy generation, with three terminals, by means of public interterminal communication, and examine the problem of characterizing all the rates at which all three terminals can generate a ``secret key,'' and -- simultaneously -- two designated terminals can generate a ``private key'' which is effectively concealed from the remaining terminal; both keys are also concealed from an eavesdropper that observes the public communication. Inner and outer bounds for the ``secret key--private key capacity region'' are derived. Under a certain special condition, these bounds coincide to yield the (exact) secret key--private key capacity region.