ESP32-Enabled Secure LiFi Sensor Nodes with Lightweight Post-Quantum Cryptography for Indoor IoT
Abstract
We describe the architecture of a prototype and design of an indoor Internet-of-Things (IoT) sensor node based on visible light communication (LiFi) and powered with an ESP32 microcontroller and a lightweight post-quantum cryptography (PQC). LiFi offers indoors high throughput and line of sight wireless connections with reduction of RF congestion although LiFi terminals still need very robust cryptographic measures against spoofing and exfiltration of data. We combine a lattice-based KEM (CRYSTALS-Kyber/ Kyber-lite style) that is our main key-encapsulation system with an efficient signature/hybrid authentication protocol to implement forward-secure and quantumresistant session keys on resource-constrained ESP32 platforms. We describe the hardware/software integration, optimization of memory and CPU using the ESP32 dual core and hardware AES, and a small protocol stack on the LiFi sensor device. Our implementation in ESP32 Kyber is feasible based on existing ESP32 Kyber-based ESP32 implementations and the literature of PQC in IoT; we give an evaluation plan and predictable latency/throughput tradeoffs of realistic deployments inside homes. The suggested architecture allows to support the implementation of privacy-sensitive LiFi sensing into the interior with security, at the same time being viable on off-the-shelf microcontroller systems.