SteaLTE: Private 5G Cellular Connectivity as a Service with Full-stack Wireless Steganography

TL;DR

This paper introduces SteaLTE, a novel LTE-compliant wireless steganography system enabling private, covert cellular slices with minimal impact on primary traffic, leveraging full-stack techniques for undetectable communication in 5G networks.

Contribution

It presents the first full-stack LTE-compliant steganographic protocol for private cellular slices, balancing undetectability and performance in 5G infrastructure.

Findings

SteaLTE causes less than 6% throughput loss in primary traffic.

It effectively mimics channel impairments to hide covert data.

The system performs well in indoor and outdoor LTE environments.

Abstract

Fifth-generation (5G) systems will extensively employ radio access network (RAN) softwarization. This key innovation enables the instantiation of "virtual cellular networks" running on different slices of the shared physical infrastructure. In this paper, we propose the concept of Private Cellular Connectivity as a Service (PCCaaS), where infrastructure providers deploy covert network slices known only to a subset of users. We then present SteaLTE as the first realization of a PCCaaS-enabling system for cellular networks. At its core, SteaLTE utilizes wireless steganography to disguise data as noise to adversarial receivers. Differently from previous work, however, it takes a full-stack approach to steganography, contributing an LTE-compliant steganographic protocol stack for PCCaaS-based communications, and packet schedulers and operations to embed covert data streams on top of traditional cellular traffic (primary traffic). SteaLTE balances undetectability and performance by mimicking channel impairments so that covert data waveforms are almost indistinguishable from noise. We evaluate the performance of SteaLTE on an indoor LTE-compliant testbed under different traffic profiles, distance and mobility patterns. We further test it on the outdoor PAWR POWDER platform over long-range cellular links. Results show that in most experiments SteaLTE imposes little loss of primary traffic throughput in presence of covert data transmissions (< 6%), making it suitable for undetectable PCCaaS networking.