Implementation of a Heterogen Multi User Key Generation System in an Indoor Environment

Using Secret Key Generation (SKG) based on RSSI measurements, we present a multi-user key generation system for secure wireless communication. The system was evaluated under three deployment scenarios: indoor-static 5 m and 10 m) and semi-indoor (25 m). In Scenario 1 (5 m), the system achieved a Key Disagreement Rate (KDR) of 34.70% and a Key Generation Rate (KGR) of 4.68 bit/s. Scenario 2 (10 m) showed improved results with a KDR of 26.23 % and a KGR of 5.00 bit/s. Meanwhile, Scenario 3(25 m) experienced a drop in performance with a KDR of 49.23 % and a KGR of 1.53 bit/s. After applying BCH error correction and universal hashing, 128-bit cryptographic keys were successfully generated and validated using NIST randomness tests. AES encryption tests confirmed key synchronization across all nodes, demonstrating the practicality of the proposed SKG system in low-to-moderate range deployments.