System and method to lock TPM always 'on' using a monitor
AssigneeMicrosoft Corporation
InventorsAlexander Frank, Paul England
Life of this patent
Estimating the term…
Abstract
A computer may be secured from attack by including a trusted environment used to verify a known monitor. The monitor may be used to determine a state of the computer for compliance to a set of conditions. The conditions may relate to terms of use, such as credits available for pay-per-use, or that the computer is running certain software, such as virus protection, or that unauthorized peripherals are not attached, or that a required token is present. The monitor may send a signal directly or through the trusted environment to a watchdog circuit. The watchdog circuit disrupts the use of the computer when the signal is not received in a given timeout period.
Claims20
A computer implementing a trusted computing base for enforcing operation of a monitor, the computer comprising:
- a processor for executing the monitor;
- a trusted environment coupled to the processor for ensuring execution of the monitor, the trusted environment adapted to receive a message from the monitor;
- a watchdog circuit coupled to the trusted environment, the watchdog circuit disrupting the computer after a period, unless the trusted environment receives the message within the period.
The computer of claim 9, wherein the token comprises a version number for use by the monitor in determining whether the monitor is the current version.
A method of encouraging a known operating state in a computer comprising:
- executing a known monitor;
- sending a signal from the known monitor to a watchdog circuit;
- and
- preventing the watchdog circuit from disrupting an operation of the computer responsive to the signal.
A watchdog circuit for use in computer comprising:
- a timer for determining a period of time;
- an input for receiving a signal to restart the timer;
- and
- an output for disrupting an operation of the computer when the signal is not received during the period of time.
Dependencies are inferred from the claim text.