Secure communication is expected to become even more critical in future 6G networks, particularly as emerging technologies such as quantum computing threaten traditional public-key encryption schemes. To explore alternative security approaches, researchers have developed a context-aware secret key generation (SKG) demonstrator that leverages physical layer properties of wireless channels to generate shared cryptographic keys. The demonstrator showcases an end-to-end SKG system built using two Universal Software Radio Peripheral (USRP) X410 devices that exchange wireless signals. By measuring reciprocal wireless channel characteristics between two legitimate users (commonly referred to as Alice and Bob), the system extracts shared randomness directly from the communication channel to generate secret keys.
A key innovation of the demonstrator is its context-aware design. A machine-learning model analyzes received channel signals and classifies the environment into different scenarios, such as line-of-sight (LoS) static, non-line-of-sight (NLoS) static, or dynamic conditions. Based on the detected context, the system automatically adjusts SKG protocol parameters to improve the number of secure bits generated while minimizing potential information leakage. The demonstrator visualizes the entire SKG process through an interactive graphical user interface (GUI). The interface displays real-time signal exchanges, context detection results, and the resulting key generation process. To make the concept tangible, the generated secret key bits are also displayed using a 3D-printed physical key with LEDs, where each LED represents a binary bit of the generated key.
Experimental evaluations show that environmental conditions significantly influence key generation performance. Dynamic wireless channels provide higher randomness and therefore allow the extraction of more secure bits compared to static environments. This highlights the advantage of adapting SKG parameters to the channel context. Overall, the demonstrator provides a practical illustration of how context-aware physical layer security techniques can enhance key generation in wireless systems, offering a promising direction for secure communication in future 6G networks.
Context-Aware_Secret_Key_Generation_Demonstrator_based_on_Physical_Layer_Security