Intentional acoustic interference causes unusual errors in the mechanics of magnetic hard disk drives in desktop and laptop computers, leading to damage to integrity and availability in both hardware and software such as file system corruption and operating system reboots. An adversary without any special purpose equipment can co-opt built-in speakers or nearby emitters to cause persistent errors. Our work traces the deeper causality of these risks from the physics of materials to the I/O request stack in operating systems for audible and ultrasonic sound. Our experiments show that audible sound causes the head stack assembly to vibrate outside of operational bounds; ultrasonic sound causes false positives in the shock sensor, which is designed to prevent a head crash.The problem poses a challenge for legacy magnetic disks that remain stubbornly common in safety critical applications such as medical devices and other highly utilized systems difficult to sunset. Thus, we created and modeled a new feedback controller that could be deployed as a firmware update to attenuate the intentional acoustic interference. Our sensor fusion method prevents unnecessary head parking by detecting ultrasonic triggering of the shock sensor.

Over the last six years, several papers demonstrated how intentional analog interference based on acoustics, RF, lasers, and other physical modalities could induce faults, influence, or even control the output of sensors. Damage to the availability and integrity of sensor output carries significant risks to safety-critical systems that make automated decisions based on trusted sensor measurement. Established signal processing models use transfer functions to express reliability and dependability characteristics of sensors, but existing models do not provide a deliberate way to express and capture security properties meaningfully.Our work begins to fill this gap by systematizing knowledge of analog attacks against sensor circuitry and defenses. Our primary contribution is a simple sensor security model such that sensor engineers can better express analog security properties of sensor circuitry without needing to learn significantly new notation. Our model introduces transfer functions and a vector of adversarial noise to represent adversarial capabilities at each stage of a sensor's signal conditioning chain. The primary goals of the systematization are (1) to enable more meaningful quantification of risk for the design and evaluation of past and future sensors, (2) to better predict new attack vectors, and (3) to establish defensive design patterns that make sensors more resistant to analog attacks.

Limiting sensitive information leakage via smart-home sensor data.

Conventional golf course fairway irrigation relies on visual observation of the turfgrass, followed by secondary considerations of short‐term weather forecasts, which oftentimes lead to ‘blanket’ applications to an entire area. Precision irrigation may achieve water use reductions by irrigating only where, when, and in the amount needed. Technology can further enhance its application; for example, using global navigation satellite system (GNSS)‐equipped soil moisture sensors for creating fairway soil moisture maps to identify variability. However, research regarding soil moisture variability on fairways at golf courses that differ by climatic region and course characteristics is limited. The objective of this case study was to report fairway soil moisture variability findings from nine golf courses in eight states in the United States that completed a soil moisture mapping protocol during 2019–2022. Each course used a handheld GNSS‐equipped soil moisture device to collect georeferenced soil moisture (percentage volumetric water content [VWC]) data from seven to 14 of their fairways. Soil moisture variability was assessed through summary statistics, box and whisker plots, and spatial maps. The mean soil moisture on fairways across courses was 22.4–48.8% VWC, the range was 27.6–43.7% VWC, and the CV was 7.5–39.4%. Box and whisker plots and spatial maps of soil moisture aided in visualizing variability within and between fairways at all courses. Results suggest that golf course fairway soil moisture variability is inevitable regardless of climatic region and course characteristics, which further reiterates the need for advanced irrigation practices and technologies for water conservation via precision irrigation.

Embedded systems that are wirelessly reprogrammed can be rendered useless by certain programming errors, excessive power consumption, or misconfigurations in the hardware. These types of situations can leave a device in a state that compromises its programmability, often rendering the device useless. Existing attempts to address the problem of robust wireless reprogramming have all been software-based solutions, that are vulnerable to certain errors, such as memory corruption, can corrupt the recovery programs. We propose a hardware-based solution to wireless reprogramming, physically separating the programmer and target device. This separation limits the propagation of errors, and ensures the device will always be recoverable. In this poster we will present the design and an early prototype of our approach -an ultra-low-power, low-cost hardware solution to ensure recovery from fatal errors and reprogrammability in wireless systems. This poster discusses the current system design, initial results, and system analysis from our current prototype. We also present future and ongoing directions, as well as key research questions.