A Low-Power Dual-Factor Authentication Unit for Secure Implantable Devices
This addresses security vulnerabilities in implantable devices for patients, though it is incremental as it builds on existing authentication methods.
The paper tackles the security of implantable medical devices by proposing a dual-factor authentication protocol combining cryptographic and touch-based authentication, resulting in a low-power implementation with 735 pW idle power and 8 μW active power.
This paper presents a dual-factor authentication protocol and its low-power implementation for security of implantable medical devices (IMDs). The protocol incorporates traditional cryptographic first-factor authentication using Datagram Transport Layer Security - Pre-Shared Key (DTLS-PSK) followed by the user's touch-based voluntary second-factor authentication for enhanced security. With a low-power compact always-on wake-up timer and touch-based wake-up circuitry, our test chip consumes only 735 pW idle state power at 20.15 Hz and 2.5 V. The hardware accelerated dual-factor authentication unit consumes 8 $μ$W at 660 kHz and 0.87 V. Our test chip was coupled with commercial Bluetooth Low Energy (BLE) transceiver, DC-DC converter, touch sensor and coin cell battery to demonstrate standalone implantable operation and also tested using in-vitro measurement setup.