Information Leakage in Index Coding

TL;DR

This paper investigates the extent of information leakage in index coding scenarios with general message distributions, providing bounds on leakage rates and establishing exact results for independent uniform messages.

Contribution

It introduces bounds on the optimal leakage rate in index coding with general message distributions and proves exact equivalence for independent uniform messages.

Findings

Bounds on leakage rates for general message distributions.

Exact leakage rate for independent uniform messages.

Equivalence of bounds in specific message distribution cases.

Abstract

We study the information leakage to a guessing adversary in index coding with a general message distribution. Under both vanishing-error and zero-error decoding assumptions, we develop lower and upper bounds on the optimal leakage rate, which are based on the broadcast rate of the subproblem induced by the set of messages the adversary tries to guess. When the messages are independent and uniformly distributed, the lower and upper bounds match, establishing an equivalence between the two rates.