Apparatus and method for preventing theft of computer devices

• US 5,892,906 A
• Filed: 07/19/1996
• Issued: 04/06/1999
• Est. Priority Date: 07/19/1996
• Status: Expired due to Term

• Current Assignee: SafeNet Incorporated (Thales SA)
• Original Assignee: Joseph Larussa, Joseph M. Kulinets, Laszlo Elteto, Wayne W. Chou
• Inventors: Elteto, Laszlo, Kulinets, Joseph M., LaRussa, Joseph, Chou, Wayne W.
• Primary Examiner(s): Palys, Joseph E.
• Application Number:
  US08/684,659
• Time in Patent Office: 991 Days
• Field of Search: 395/186, 395/188.01, 395/187.01, 395/183.12, 395/652, 380/3, 380/4, 380/23, 380/25
• US Class Current: 726/19
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06F 21/34 involving the use of external additional devices, e.g. dongles or smart cards
• CPC Class Codes: G06F 21/575 Secure boot
• CPC Class Codes: G06F 21/88 Detecting or preventing theft or loss
• CPC Class Codes: G06F 2211/1097 Boot, Start, Initialise, Power
• CPC Class Codes: G06F 2221/2105 Dual mode as a secondary aspect
• CPC Class Codes: G06F 2221/2147 Locking files

Abstract

Apparatus and method for discouraging computer theft. The apparatus and method requires that a password or other unique information be supplied to the computer before the computer BIOS routines can be completely executed. A BIOS memory storing the BIOS routines includes a security routine which will determine whether or not the required password entered by the user, or a known quantity read from an externally connected memory device is present. The security function stored within the BIOS memory also includes an administration function which permits the computer to be either placed in a locked state, thereby requiring password or the known quantity read from an externally connected memory device to be present each time the computer is booted up. The administration function also permits an unlock state which permits the computer boot up process to complete without entering any password or externally supplied quantity. The external memory location is consulted during each boot up sequence, to determine whether the computer has been placed in the locked or in the unlocked state. If the security depends upon the supply of the known quantity from an externally connected memory device, the computer will be inoperable to anyone not in possession of the external memory device. In the event that the external memory location bearing the locked or unlocked code is removed, the security function assumes the computer to be in the locked state, thus frustrating avoidance of the locked state by tampering with the external memory.

Claims

1. An apparatus for preventing theft of a personal computer comprising:

a personal computer having a processing unit having a BIOS routine stored in a BIOS memory, which initiates operation of an operating system of said computer, said BIOS routine including a security function which requests a unique quantity from a user before permitting said computer operating system to initiate operations, said BIOS security function being implemented by a series of programming steps which perform the function of checking the contents of a random access memory within said computer to determine if the security function is on or off, requesting a user to enter a said unique quantity if said security function is on, comparing said quantity with a quantity previously stored in said BIOS memory, and enabling said BIOS to continue execution to invoke said operating system if said quantities match, wherein said security function includes a series of programming steps which provide an administration function, said administration function providing a lock function by programming said random access memory with a lock code at the request of a user which requires entry of said unique quantity each time said computer is operated, or an unlock function for programming said random access memory with an unlock code at the request of the user which does not require the entry of a user supplied quantity for subsequent operation.

2. The apparatus according to claim 1 wherein said security function includes stored in said BIOS memory a stored serial number, and which includes a series of programming steps which verify if a user supplied quantity is equivalent to said serial number.

3. The apparatus according to claim 2 wherein said administration function includes a series of computing steps which permit a user to change said quantity stored in said BIOS memory following entry of a previously entered quantity.

4. The apparatus according to claim 1 wherein said random access memory is a battery operated random access memory.

5. A method for protecting a computer from unauthorized use by storing in a BIOS memory containing BIOS instructions a security function which is capable of inhibiting operation of said computer, said security function comprising the following programming steps:

checking the contents of an internal random access memory for a locked state command to see if said computer was previously placed in a locked state;

if said computer is in the locked state, requesting said user to enter a password;

comparing said password with a password previously entered into said BIOS memory; and

inhibiting execution of said BIOS instructions if said passwords do not agree.

6. The method according to claim 5 further comprising storing a programming routine in said BIOS memory which permits a user to place the computer in an unlocked state following verification that said passwords agree.

7. The method according to claim 5 wherein said programming step for placing said computer in an unlocked state deletes from said internal memory said locked state command.

8. A method for inhibiting access to a personal computer device comprising:

storing within a BIOS memory having BIOS instructions for executing a boot up sequence, a public key as well as instructions to inhibit execution of a portion of said sequence of said instructions until a users authority is validated;

storing a unique code identifying said computer device into said BIOS memory;

calculating a digital signature from said unique code;

at boot up time for said personal computer, prompting a user to enter a password;

entering said digital signature in lieu of a password;

verifying said digital signature from said stored public key and said unique code thereby validating said users authority; and

entering an administration mode which permits said user to enter a personal password into said BIOS memory for future use and to continue said boot up sequence by said computer.

9. The method according to claim 8 wherein said BIOS instructions request said user to enter said user password during future execution of said instructions to boot up said computer, and inhibits said boot up sequence if said user does not enter said password.

10. The method according to claim 9 wherein said administration mode permits selection of a locking state by said user which inhibits completion of each subsequent boot up sequence unless a user password is entered each time said boot up instructions are executed.

11. The method according to claim 10 wherein said locking state is effected by writing a locking code to an internal memory which is read each time a subsequent execution sequence of BIOS instructions occurs, and said BIOS instructions continuing execution only if said user enters a valid password.

12. The method according to claim 11 wherein said user is given an option by said administration mode following verification of said entered password to exit said locking state.

13. The method according to claim 12 wherein said BIOS instructions exit said locking state by deleting said locking code from said internal memory.

15. The anti-theft device according to claim 13 wherein during execution of said BIOS routines, said security function prompts a user to connect said external memory device to said computer if said computer is in the locked state.

14. An anti theft protection device for a personal computer comprising:

a programmable memory within said computer for storing BIOS routines for booting up said computer as well as a security routine having unique security information which communicates with an internal memory and an externally connected device having unique information contained therein;

a detachable external memory device containing said unique information which is used by said security routine to enable execution of said BIOS routine when said unique security information matches said unique information when said internal memory includes a locking code, whereby said BIOS routine can only be completely executed if said external memory device is in communication with said computer;

wherein said security routine include an Administration function which permits said user to enter a command to unlock said computer from a locked state whereby said BIOS routines may be subsequently executed in the absence of said external device; and

wherein said administration function unlocks said computer from a locked state by inserting unlocking data in a specified location in said internal memory of said computer, and said BIOS routines reads said location each time said computer is activated, permitting execution of said BIOS routines if said unlocking data is present in said internal memory.

16. The device according to claim 14 wherein said internal memory is a battery operated random access memory.