A low-power dual-factor authentication unit for secure implantable devices

Abstract: 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 µW 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. ©2020 Paper presented at the 2020 IEEE Custom Integrated Circuits Conference (CICC 2020), March 22-25, 2020, Boston, Mass.Analog Devices Inc

A stochastic optimization model for real-time operation of reservoirs using uncertain forecasts

A real-time operation model primarily useful for daily operation of reservoirs is developed. This model is based on a chance constraint formulation and assumes a particular form of the linear decision rule. It uses the conditional distribution function (CDF) of actual streamflows conditioned on the forecasted values. These CDF's are constructed by incorporating the statistical properties of forecast errors for different time steps. The objective considered is the minimization of weighted probable deviations from storage and release targets. These weights are surrogates for the actual loss functions, and the probable deviations are functions of the reliability levels specified in the model. With the use of target values for release and storage, this model is capable of using a release policy that is a subset of a seasonal policy and overcomes the myopic (short-sighted) nature of operation. Simulation of actual operation, using this model for a hypothetical reservoir, demonstrates the feasibility and efficiency of this approach. This model is shown to be applicable for a system of reservoirs. The restrictions associated with the use of a linear decision rule are shown to be invalid for this model