Multi-Transmitter Coded Caching with Secure Delivery over Linear Networks -- Extended Version

TL;DR

This paper introduces secure multi-transmitter coded caching schemes over linear networks, ensuring data privacy against eavesdroppers while analyzing their performance and demonstrating minimal security-related costs.

Contribution

It presents new secure coded caching schemes with closed-form delay and key storage expressions, including decentralized scenarios, and compares their performance.

Findings

Security incurs negligible memory cost at scale.

Secure coding delay becomes asymptotically equal in centralized and decentralized schemes.

Numerical results confirm efficient secure caching with minimal security overhead.

Abstract

In this paper, we consider multiple cache-enabled end-users connected to multiple transmitters through a linear network. We also prevent a totally passive eavesdropper, who sniffs the packets in the delivery phase, from obtaining any information about the original files in cache-aided networks. Three different secure centralized multi-transmitter coded caching scenarios namely, secure multi-transmitter coded caching, secure multi-transmitter coded caching with reduced subpacketization, and secure multi-transmitter coded caching with reduced feedback, are considered and closed-form coding delay and secret shared key storage expressions are provided. As our security guarantee, we show that the delivery phase does not reveal any information to the eavesdropper using the mutual information metric. Moreover, we investigate the secure decentralized multi-transmitter coded caching scenario, in which there is no cooperation between the clients and transmitters during the cache content placement phase and study its performance compared to the centralized scheme. We analyze the system's performance in terms of Coding Delay and guarantee the security of our presented schemes using the Mutual Information metric. Numerical evaluations verify that security incurs a negligible cost in terms of memory usage when the number of files and users are scaled up, in both centralized and decentralized scenarios. Also, we numerically show that by increasing the number of files and users, the secure coding delay of centralized and decentralized schemes became asymptotically equal.