Altering Sampling Rate to Thwart Attacks that Involve Analyzing Hardware Sensor Output

摘要

A hardware sensor and a hardware user-input component are integrated in a portable electronic device. The hardware sensor is operable to produce hardware sensor output indicative of orientation or motion or both of the device within its environment. The hardware user-input component has multiple elements operable to accept user input through touch. A user-input driver and the device's operating system are jointly operable to detect touch events involving the elements. A software application stored in the device's memory is executable by the device's processor as a process. A sensor driver or the operating system or both are configured to control what hardware sensor output, if any, is receivable by the process. This control may thwart an attack based on analysis of the hardware sensor output, the attack designed to deduce what user input has been made via multiple elements of the hardware user-input component.

主权项

1. A method performed in a portable electronic device, the method comprising:
controlling how hardware sensor output, if any, is available to a process resulting from execution of a software application by a processor of the portable electronic device, as follows:
making any hardware sensor output sampled during those time periods throughout which the process is running in foreground available to the process at a higher sampling rate; andmaking any hardware sensor output sampled during those time periods throughout which the process is running in background available to the process at a lower sampling rate, wherein the hardware sensor output is indicative of orientation or motion or both of the portable electronic device within its environment, and the hardware sensor output is produced by a hardware sensor integrated in the portable electronic device, wherein the portable electronic device comprises a hardware user-input component integrated in the portable electronic device, the hardware user-input component having multiple elements operable to accept user input through touch, and wherein the process runs in the foreground during times when the operating system of the portable electronic device is operable to notify the process of any detected touch events involving the elements, and the process runs in the background during times when the operating system is operable not to notify the process of any detected touch events involving the elements.