Wireless channel based real time key generation secures communications
gr-PHYSEC: Real-time Channel-based Key Generation for Physical Layer Secure Wireless Communications
Cryptography and Security
Summary
Wireless communications can be vulnerable to eavesdropping, especially when devices connect directly or move around. The authors developed a system called gr-PHYSEC that uses the unique randomness of the wireless channel between two trusted devices to create secret keys automatically. They embedded a machine learning model in a popular radio software framework to generate and verify these keys on the fly. Tested on real robots and radios, their method produced reliable keys that passed official randomness tests and can directly encrypt data.
What this means in practice
- •For wireless network engineers: Implement real-time physical layer key generation in wireless systems to enhance security without relying on pre-shared keys.
- •For industrial robotics teams: Secure robot communications in dynamic environments using software-defined radios that generate encryption keys from channel characteristics.
Authors
Jose Angel Sanchez Viloria, George Sklivanitis, Dimitris Pados
Abstract
Securing wireless communication against eavesdropping is critical, particularly in dynamic and decentralized environments. We present gr-PHYSEC, a new GNU Radio out-of-tree (OOT) module for real-time physical-layer key generation. Unlike traditional key generation that relies on pre-shared secrets or computational complexity, our approach derives symmetric keys from the wireless channel's inherent randomness. We embed a trained neural network within GNU Radio to extract channel features between trusted parties (Alice and Bob) during probe exchanges. These features are quantized into binary keys, reconciled via Reed-Solomon encoding, and further secured with SHA-512 hashing. The generated keys are then directly used to encrypt data. Real-world experiments at the FAU CAAI connected robotics testbed using ADALM Pluto software-defined radios and NVIDIA Jetson Orin validate the approach with ground robotic platforms. Results demonstrate low key disagreement rates and strong randomness, as verified by the NIST test suite for random and pseudorandom number generators for cryptographic applications. This integration showcases how GNU Radio can support real-time AI-driven security solutions, pushing the boundaries of software-defined secure communication. The source code for this project is available at: https://github.com/C2A2-at-Florida-Atlantic-University/gr-PHYSEC