Inactivity monitor for trusted personal computer system

Abstract

A personal computer system is described, having security features enabling control over access to data retained in such a system. The system has a normally closed enclosure, at least one erasable memory element for selective activation to active and inactive states and for receiving and storing a privileged access password when in the active state, an option switch operatively connected with the erasable memory element for setting the erasable memory element to the active and inactive states, a tamper detection switch operatively connected with the erasable memory element for detecting opening of the enclosure, and a system processor operatively connected with the erasable memory element for controlling access to at least certain levels of data stored within the system by distinguishing between entry and non-entry of any stored privileged access password and between detection and non-detection of opening of the enclosure by the tamper detection switch. In addition, an inactivity monitor is provided for measuring the time period between successive uses of the system and for determining whether or not the measured time period exceeds a specified inactivity period. A utility is provided for rendering the monitor enabled. When the enabled monitor determines that the measured time exceeds the specified time, power-up of the system is prevented until the privileged access password (or a power-on password) is successfully entered into the system by a user.