Personal computer security system

• US 5,675,321 A
• Filed: 11/29/1995
• Issued: 10/07/1997
• Est. Priority Date: 11/29/1995
• Status: Expired due to Fees

• Current Assignee: Randall C. McBride
• Original Assignee: Randall C. McBride
• Inventors: McBride, Randall C.
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US08/563,988
• Time in Patent Office: 678 Days
• Field of Search: 340/568, 340/571, 340/652, 340/687, 340/522, 340/529, 340/511, 340/825.31, 340/825.32, 340/825.34, 395/186, 395/188.01, 395/726, 395/427, 395/491, 364/222.5, 364/286.4, 364/286.5, 364/969.2, 364/969.4, 380/4, 380/25, 235/382, 235/382.5, 379/377, 379/95
• US Class Current: 340/568.2
• CPC Class Codes: G08B 13/1409 for removal detection of electrical appliances by detecting their physical disconnection from an electrical system, e.g. using a switch incorporated in the plug connector

Abstract

The personal computer security apparatus of the present invention provides a security architecture embedded within the personal computer itself to provide a practical level of security to thereby discourage theft of the personal computer. Apparatus are provided to monitor the continuity of the connection to the telephone line to which the personal computer is connected. Loss of voltage continuity on the telephone line for greater than a predetermined period of time is indicative of an individual unplugging the personal computer from the phone jack in order to enable the person to move the personal computer. Motion sensor switches are optionally provided to detect physical movement of the personal computer in excess of a predetermined minimum allowable range of motion. The apparatus generates an audible alarm in response to the detection of a person'"'"'s attempt to relocate the personal computer without properly disabling the security software via the keyboard. In addition to the audible alarm that is generated, software resident on the personal computer can obliterate the data stored on the hard disk by reformatting the hard drive to thereby thwart a thief from having access to the data stored on the personal computer.

Claims

1. Apparatus for providing security to prevent unauthorized removal of a personal computer from a location at which the personal computer is resident, comprising:

means for monitoring the presence of a reference signal produced by a substantially immutable reference signal source;

means for monitoring the presence of a reference signal produced by a substantially immutable reference signal source;

means, responsive to said monitoring means determining a variance of said reference signal in excess of a predetermined threshold, for generating an alarm indicating unauthorized movement of said personal computer; and

means, responsive to said alarm indication, for activating at least one theft deterrence action.

2. The apparatus of claim 1 wherein said monitoring means comprises:

means for determining the presence of a predetermined voltage present on a telephone line to which said personal computer is connected.

3. The apparatus of claim 2 wherein said monitoring means further comprises:

means for periodically validating said predetermined voltage by generating an off-hook condition on said telephone line to elicit dial tone from telephone company equipment serving said telephone line.

4. The apparatus of claim 1 wherein said monitoring means comprises:

at least one motion sensor mounted within said personal computer for generating a signal indicative of absence of motion in a predetermined plane of reference in excess of a predetermined amount.

5. The apparatus of claim 1 wherein said monitoring means comprises:

means for determining the presence of a predetermined voltage present on a telephone line to which said personal computer is connected;

at least one motion sensor mounted within said personal computer for generating a signal indicative of absence of motion in a predetermined plane of reference in excess of a predetermined amount.

6. The apparatus of claim 5 wherein said alarm generating means comprises:

means for verifying a concurrent determined absence of said reference signal for greater than a predetermined period of time from both said predetermined voltage determining means and said at least one motion sensor.

7. The apparatus of claim 1 wherein said activating means comprises:

means for producing an audible alarm.

8. The apparatus of claim 1 wherein said activating means comprises:

means for activating said personal computer to display a query to a user; and

means, responsive to a user failing to input a valid response to said query, for producing an audible alarm.

9. The apparatus of claim 8 wherein said activating means further comprises:

means for disabling access to data stored in said personal computer.

10. The apparatus of claim 9 wherein said disabling access means comprises:

means for reformatting memory resident in said personal computer.

11. A method for providing security to prevent unauthorized removal of a personal computer from a location at which the personal computer is resident, comprising the steps of:

monitoring the presence of a reference signal produced by a substantially immutable reference signal source;

generating, in response to determination of variance of said reference signal in excess of a predetermined threshold, an alarm indicating unauthorized movement of said personal computer; and

activating, in response to said alarm indication, at least one theft deterrence action.

12. The method of claim 11 wherein said step of monitoring comprises:

determining the presence of a predetermined voltage present on a telephone line to which said personal computer is connected.

13. The method of claim 12 wherein said step of monitoring further comprises:

periodically validating said predetermined voltage by generating an off-hook condition on said telephone line to elicit dial tone from telephone company equipment serving said telephone line.

14. The method of claim 11 wherein said step of monitoring comprises:

using at least one motion sensor mounted within said personal computer to generate a signal indicative of absence of motion in a predetermined plane of reference in excess of a predetermined amount.

15. The method of claim 11 wherein said step of monitoring comprises:

determining the presence of a predetermined voltage present on a telephone line to which said personal computer is connected;

using at least one motion sensor mounted within said personal computer to generate a signal indicative of absence of motion in a predetermined plane of reference in excess of a predetermined amount.

16. The method of claim 15 wherein said step of alarm generating comprises:

verifying a concurrent determined absence of said reference signal for greater than a predetermined period of time from both said step of predetermined voltage determining and said at least one motion sensor.

17. The method of claim 11 wherein said step of activating comprises:

producing an audible alarm.

18. The method of claim 11 wherein said step of activating comprises:

activating said personal computer to display a query to a user; and

producing, in response to a user failing to input a valid response to said query, an audible alarm.

19. The method of claim 18 wherein said step of activating further comprises:

disabling access to data stored in said personal computer.

20. The method of claim 19 wherein said step of disabling access comprises:

reformatting memory resident in said personal computer.