A Novel Physical Layer Encryption Algorithm for LoRa

LoRa has been widely used in the Internet of Things (IoT) recently for its advantages of long distance and low power consumption. However, the security problem restricts its practical application scenarios. The existing Advanced Encryption Standard (AES) technology has high computational complexity and high energy consumption for LoRa terminals with limited hardware resources. Therefore, this letter proposes a novel physical layer encryption algorithm based on LoRa modulation characteristics, which is suitable for low-cost LoRa terminals. The algorithm combines the secret key extraction approach based on Received Signal Strength Indicator (RSSI) with the secret sharing scheme based on Chinese Remainder Theorem (CRT). Simulation results show that the proposed algorithm can protect the LoRa transmission bits from eavesdroppers. While, compared with the conventional LoRa without security, the proposed algorithm has no bit error rate (BER) performance loss with different SNR and will not cause more serious spectrum leakage under different synchronization offsets.