Fundamental Rate Limits of Physical Layer Spoofing

TL;DR

This paper characterizes the maximum achievable rate at which a legitimate spoofer can replace a malicious message at Bob's receiver in a wireless system, using a novel combined spoofing strategy and optimizing power allocation.

Contribution

It introduces a new combined spoofing method and derives the maximum spoofing rates under different decoding strategies at Bob.

Findings

Maximum spoofing rate with interference as noise (TIN)

Maximum spoofing rate with successive interference cancelation (SIC)

Optimal power allocation strategies for spoofing

Abstract

This letter studies an emerging wireless communication intervention problem at the physical layer, where a legitimate spoofer aims to spoof a malicious link from Alice to Bob, by replacing Alice's transmitted source message with its target message at Bob side. From an information-theoretic perspective, we are interested in characterizing the maximum achievable spoofing rate of this new spoofing channel, which is equivalent to the maximum achievable rate of the target message at Bob, under the condition that Bob cannot decode the source message from Alice. We propose a novel combined spoofing approach, where the spoofer sends its own target message, combined with a processed version of the source message to cancel the source message at Bob. For both cases when Bob treats interference as noise (TIN) or applies successive interference cancelation (SIC), we obtain the maximum achievable spoofing rates by optimizing the power allocation between the target and source messages at the spoofer.