Authorized and Rogue Device Discrimination Using Dimensionally Reduced RF-DNA Fingerprints

Unauthorized network access and spoofing attacks at wireless access points (WAPs) have been traditionally addressed using bit-centric security measures and remain a major information technology security concern. This has been recently addressed using RF fingerprinting methods within the physical layer to augment WAP security. This paper extends the RF fingerprinting knowledge base by: 1) identifying and removing less-relevant features through dimensional reduction analysis (DRA) and 2) providing a first look assessment of device identification (ID) verification that enables the detection of rogue devices attempting to gain network access by presenting false bit-level credentials of authorized devices. DRA benefits and rogue device rejection performance are demonstrated using discrete Gabor transform features extracted from experimentally collected orthogonal frequency division multiplexing-based wireless fidelity (WiFi) and worldwide interoperability for microwave access (WiMAX) signals. Relative to empirically selected full-dimensional feature sets, performance using DRA-reduced feature sets containing only 10% of the highest ranked features (90% reduction), includes: 1) maintaining desired device classification accuracy and 2) improving authorized device ID verification for both WiFi and WiMAX signals. Reliable burst-by-burst rogue device rejection of better than 93% is achieved for 72 unique spoofing attacks and improvement to 100% is demonstrated when an accurate sample of the overall device population is employed. DRA-reduced feature set efficiency is reflected in DRA models requiring only one-tenth the number of features and processing time.