Post Quantum Secure Communication Protocol with Ultra Low-Power Hardware Solution for Ingestible Medical Device

Ingestible electronics offer a noninvasive way to monitor important physiological signals from the gastrointestinal (GI) tract, which may open a new era in healthcare. However, it faces challenges with energy constraints and data privacy. Attacks on unprotected wireless communication can result in dangerous outcomes. In addition, conventional cryptography schemes are proven vulnerable to quantum computer attacks. Previous works either do not ensure post-quantum security or overlook the need for low energy consumption. Thus, we propose an ultra low-power hardware solution which is post-quantum secure protocol for an ingestible device. First, by combining Lightweight Cryptography (LWC) and mutually authenticated key exchange (MAKE) in Post-Quantum Cryptography (PQC), we reduce the energy consumption of enc/decryption by 59.12/61.42% by using LWC and that of key exchange with mutual authentication 75.82% by not including expensive post-quantum secure digital signature algorithm. In addition to the proposed protocol, we take a duty-cycling approach with a timer to wake the device from deep sleep mode (consuming less than 0.00025 mA). Based on our analysis for a practical scenario, we show that the overhead of cryptographic operations is compensated by using duty-cycling resulting in the lowest energy mode in hardware. Even when calling the most expensive cryptographic operation, PQC-based key exchange, for each data communication session, we can save energy by at least 67.66×.