Secure Communications for the Two-user Broadcast Channel with Random Traffic

TL;DR

This paper analyzes the stability region of a two-user broadcast channel with bursty traffic and security constraints, employing full-duplex jamming at the secure receiver to maintain secrecy and examining the impact of self-interference.

Contribution

It derives the stability regions for the two-user broadcast channel with secrecy constraints under various decoding schemes and analyzes the effect of self-interference.

Findings

Stability region depends on decoding scheme and self-interference cancellation.

Full-duplex jamming enhances secrecy but affects stability.

Secrecy constraints influence the maximum throughput and stability region.

Abstract

In this work, we study the stability region of the two-user broadcast channel (BC) with bursty data arrivals and security constraints. We consider the scenario, where one of the receivers has a secrecy constraint and its packets need to be kept secret from the other receiver. This is achieved by employing full-duplexing at the receiver with the secrecy constraint, so that it transmits a jamming signal to impede the reception of the other receiver. In this context, the stability region of the two-user BC is characterized for the general decoding case. Then, assuming two different decoding schemes the respective stability regions are derived. The effect of self-interference due to the full-duplex operation on the stability region is also investigated. The stability region of the BC with a secrecy constraint, where the receivers do not have full duplex capability can be obtained as a special case of the results derived in this paper. In addition, the paper considers the problem of maximizing the saturated throughput of the queue, whose packets does not require to be kept secret under minimum service guarantees for the other queue. The results provide new insights on the effect of the secrecy constraint on the stability region of the BC. In particular, it is shown that the stability region with secrecy constraint is sensitive to the coefficient of self-interference cancelation under certain cases.