Secure Coded Caching with Colluding Users

TL;DR

This paper studies secure coded caching systems that protect against colluding users, modeling the problem as a flow network and establishing bounds on the system's capacity to optimize data transmission.

Contribution

It introduces a network information-theoretic framework for secure coded caching and proposes a scheme achieving near-optimal capacity bounds under certain conditions.

Findings

Proposed a coded caching scheme with low load secure data transmission.

Established inner and outer bounds on the capacity region.

Showed the scheme is order optimal in specific scenarios.

Abstract

In a secure coded caching system, a central server balances the traffic flow between peak and off-peak periods by distributing some public data to the users' caches in advance. Meanwhile, these data are securely protected against the possible colluding users, who might share their cache. We model the system as a flow network and study its capacity region via a network information-theoretic approach. Due to the difficulty of characterizing the capacity region straightforwardly, our approach is two folded from the perspective of network information theory. On one hand, we identify the inner bound of capacity region by proposing a coded caching scheme to achieve a low load secure data transmission. On the other hand, we also establish outer outer bounds on the capacity region, which show that our proposed scheme is order optimal in general under specific circumstance.