Electronic lock system and method for its use

• US 7,009,489 B2
• Filed: 06/14/2002
• Issued: 03/07/2006
• Est. Priority Date: 06/14/2002
• Status: Active Grant

• Current Assignee: Sentrilock Incorporated
• Original Assignee: Sentrilock Incorporated
• Inventors: Fisher, Scott R.
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): AU, SCOTT D
• Application Number:
  US10/172,316
• Publication Number:
  US 20030231102A1
• Time in Patent Office: 1,362 Days
• Field of Search: 340/5.7, 340/5.73, 340/5.6, 340/825, 340/3.1, 340/3.7, 340/5.26, 70/63, 109 45- 49, 235/492, 235/382, 235/382.5
• US Class Current: 340/5.7
• CPC Class Codes: E05B 19/0005 Key safes E05B35/086 takes precedence
• CPC Class Codes: G07C 2209/62 Comprising means for indicating the status of the lock
• CPC Class Codes: G07C 9/00571 operated by interacting with a central unit
• CPC Class Codes: G07C 9/00912 for safes, strong-rooms, vaults or the like
• CPC Class Codes: G07C 9/21 having a variable access code
• CPC Class Codes: G07C 9/27 with central registration

Abstract

An improved electronic lock system is provided for use with real estate lock boxes where there is the need for many people to access the secured compartment of the lock box in a controlled manner. Each user has an identification card with a non-volatile secure memory (known as a “smart card”), for exchanging data with the lock box, and with a portable computer capable of reading data from the smart card; or a cell phone can be used to gain access information from a central computer. The user first inserts the smart card into the connector attached to the lock box; the lock box reads the user'"'"'s ID stored in the smart card memory and records this information in lock box memory. The lock box then transfers its access code information and other data to the smart card for further processing. The user then inserts the smart card in a portable card reader to learn the access code, or calls a central computer via a mobile phone system and interacts with the computer to elicit the necessary access code information. The access code is then manually keyed into the lock box keypad by the user to obtain access to the secure compartment.

Claims

1. A method for operating an electronic lock box system, said method comprising:

(a) providing an electronic lock box having a compartment with a controlled access member, a first memory circuit for storage of data, a first keypad, a first communications port, and a first processing circuit;

(b) providing a portable computer having a second memory circuit for storage of data, a second keypad, a display, a second communications port, and a second processing circuit;

(c) providing a portable memory device containing a non-volatile third memory circuit;

(d) coupling said portable memory device to said first communications port of the electronic lock box so as to permit communications therebetween, and loading access code information from said first memory circuit to said third memory circuit;

(e) uncoupling said portable memory device from said first communications port of the electronic lock box;

(f) coupling said portable memory device to said second communications port of the portable computer so as to permit communications therebetween, and reading said access code information from said third memory circuit to said second memory circuit;

(g) entering identification information using said second keypad, and if the identification information is correct as determined by said portable computer, displaying said access code information on said display to a human user; and

(h) entering said access code information using said first keypad, and if the access code information is correct as determined by said first processing circuit, releasing said controlled access member of the compartment.

2. The method as recited in claim 1, wherein said access code information comprises a random number generated by said electronic lock box.

3. The method as recited in claim 1, wherein said access code information is encrypted and changes value from one method step to the next.

4. The method as recited in claim 1, wherein said access code information can be used only a single time and within a predetermined time window, after which the access code information automatically expires on said electronic lock box.

5. The method as recited in claim 1, wherein said access code information is displayed along with showing instructions.

6. The method as recited in claim 1, wherein said access code information is displayed only upon at least one oft-be following conditions being correct:

(a) time of day;

(b) day ofweek;

(e) association membership;

(d) use'"'"'s personal identification number;

(e) use'"'"'s status being active; and

(I) showing by appointment only.

7. The method as recited in claim 1, wherein successful accesses to said electronic lock box are stored in said first memory circuit as an access log, which may be downloaded onto said third memory circuit using a predetermined command entered at said first keypad.

8. The method as recited in claim 1, wherein said first processing circuit of the electronic lock box frequently enters a sleep state, and is awakened by one of the following events:

(a) coupling of said portable memory device to said first communications port;

(b) a key press of said first keypad; and

(c) expiration of a time interval of a periodic timer circuit.

9. The method as recited in claim 1, wherein said controlled access member is actuated by a rotating motor drive when said motor drive rotates in a first direction;

and when said motor drive rotates in a second, opposite direction upon the occurrence of an appropriate command, a shackle release occurs.

10. A method for operating an electronic lock box system, said method comprising:

providing an electronic lock box having a first computer;

providing a portable computer having a display;

generating, at said first computer, a random number;

determining, at said portable computer, whether a user has proper clearance to allow access to said electronic lock box, and if so displaying an appropriate access code on said display, said appropriate access code being based upon said random number; and

entering said appropriate access code on a keypad of said electronic lock box, and thereafter releasing a controlled access member to obtain entry to a compartment of said electronic lock box.

11. The method as recited in claim 10, further comprising the steps of:

coupling a portable memory card to said first computer and transferring said random number from said first computer to said portable memory card;

disengaging said portable memory card from said first computer, and

thereafter, coupling said portable memory card to said portable computer and transferring said random number from said portable memory card to said portable computer.

12. The method as recited in claim 10, wherein said appropriate access code has the same numeric value as said random number.

13. The method as recited in claim 10, wherein said appropriate access code is encrypted and does not have the same value as said random number, and said first computer executes a computer program that generates a numeric value that corresponds to said encrypted access code, thereby allowing entry to said compartment.

14. The method as recited in claim 10, wherein said appropriate access code can be used only a single time and within a predetermined time window, alter which said appropriate access code automatically expires on said first computer.

15. The method as recited in claim 10, wherein said appropriate access code is displayed only upon at least one of the following conditions being correct:

(a) time of day;

(b) day ofweek;

(c) association membership;

(d) user'"'"'s personal identification number;

(e) user'"'"'s status being active; and

(f) showing by appointment only.

16. The method as recited in claim 10, wherein successful accesses to said electronic lock box are stored in a memory circuit of said first computer as an access log, which may be downloaded onto said portable memory card using a predetermined command.

17. The method as recited in claim 10, wherein said controlled access member is actuated by a rotating motor drive when said motor drive rotates in a first direction;

and when said motor drive rotates in a second, opposite direction upon the occurrence of an appropriate command, a shackle release occurs.

18. A method for operating an electronic lock box system, said method comprising:

providing an electronic lock box having a first computer;

providing a second computer at a remote location from said first computer;

providing a portable communications device used by a human user;

providing a communication link between said second computer and said portable communications device;

generating, at said first computer, a first plurality of pseudo random numbers that change at predetermined time intervals using a predetermined algorithm in conjunction with first predetermined seed data;

generating, at said second computer, a second plurality of pseudo random numbers that change at predetermined time intervals using a predetermined algorithm in conjunction with second predetermined seed data, in which said first and second predetermined seed data are the same for said electronic lock box;

accessing, using said portable communications device, said second plurality of pseudo random numbers over said communications link and thereby obtaining an access code; and

entering said access code on a keypad at said first computer, and thereafter releasing a controlled access member to obtain entry to a compartment of said electronic lock box.

19. The method as recited in claim 18, wherein said access code has the same numeric value as said one of said first plurality of pseudo random numbers at a particular moment in time, and wherein access code has the same numeric value as said one of said second plurality of pseudo random numbers at the same said particular moment in time.

20. The method as recited in claim 18, wherein said first plurality of pseudo random numbers and said second plurality of pseudo random numbers are both generated using a linear congruential random number generator that executes at both said first computer and at said second computer.

21. The method as recited in claim 18, wherein, using said portable communications device, the step of accessing said second plurality of pseudo random numbers over said communications link involves a mobile telephone, and the human user listens to computer-generated voice data transmitted by said second computer, which comprises a central clearinghouse computer.

22. The method as recited in claim 18, wherein, using said portable communications device, the step of accessing said second plurality of pseudo random numbers over said communications link involves a computer network connection, and the human user views data on a computer display associated with said portable communications device, in which said data is transmitted by said second computer, which comprises a central clearinghouse computer.

23. The method as recited in claim 18, wherein a clock circuit associated with said first computer is temperature compensated so as to produce said predetermined time intervals which are substantially in close synchronization with said predetermined time intervals produced at said second computer.

24. A method of operating an electronic lock box system, said method comprising:

providing a lock box with a secure compartment therein and a shackle for attachment to a fixed object;

providing a secure memory device;

providing a communications link used for exchanging data between said secure memory device and said lock box;

providing a portable computer that is capable of reading said secure memory device, said portable computer having a visual display device;

coupling said secure memory device and said lock box in such a way so as to permit communication between the secure memory device and the lock box through the communications link;

storing lock box configuration data and storing secure compartment access code data in said secure memory device through the communications link;

de-coupling said secure memory device from said lock box; and

coupling said secure memory device to said portable computer, reading said secure compartment access code data, and, by use of said visual display device of the portable computer, conditionally revealing said secure compartment access code data to a human user.

31. The method as recited in claim 24, further comprising the step of:

entering said secure compartment access code data on a keypad at said lock box, and thereafter releasing a controlled access member to obtain entry to said secure compartment of the lock box.

25. A method of operating an electronic lock box system, said method comprising:

providing an electronic lock box with a secure compartment therein and a shackle for attachment to a fixed object;

providing a mobile communications device, said mobile communications device having a visual display device;

providing a central clearinghouse computer at a remote location from said electronic lock box;

establishing a communication link between said mobile communications device and said central clearinghouse computer;

thereafter, transmitting to said central clearinghouse computer unique identification information about said electronic lock box and unique identification information about a user requesting access to said electronic lock box;

thereafter, conditionally transmitting from said central clearinghouse computer a secure compartment access code data to said mobile communications device, and, by use of said visual display device of the mobile communications device, revealing said secure compartment access code data to a human user; and

thereafter, manually entering said secure compartment access code data on a keypad at said electronic lock box, and thereafter releasing a controlled access member to obtain entry to said secure compartment.

26. The method as recited in claim 25, wherein said secure compartment access code data is in the form of digital data that can be displayed on the visual display device of said mobile communications device.

27. A method of maintaining an electronic lock system'"'"'s synchronization of time-refreshed progressive security access codes, said method comprising:

providing a central clearinghouse computer at a remote location, a first computer at an electronic lock, an ambient temperature sensor at said electronic lock, and a clock oscillator circuit having a known temperature drift coefficient at said electronic lock;

reading an ambient temperature at predetermined regular intervals using said ambient temperature sensor;

accumulating clock oscillator dine drift, based on a plurality of electronic lock ambient temperature values taken at predetermined time intervals;

generating a first plurality of time-refreshed progressive security access codes at said first computer;

generating a second plurality of time-refreshed progressive security access codes at said central clearinghouse computer; and

adjusting a rate of new access code computation at said first computer using said accumulated clock oscillator time drift, to maintain synchronization between said first plurality of time-refreshed progressive security access codes and second plurality of time-refreshed progressive security access codes.

28. An electronic lock box system, comprising:

an electronic lock box attached to a fixed object, said lock box comprising;

a first electrical power source, a first processing circuit, a first memory circuit, a first communications port, an ambient temperature sensor, and a secure key compartment;

a portable computer comprising;

a second electrical power source, a second processing circuit, a second memory circuit, and a second communications port;

said first processing circuit, first memory circuit, and first communications port are configured to exchange data wit a secure memory device; and

said second processing circuit, second memory circuit, and second communications port are configured to exchange data with said secure memory device, and are further configured to restrict access to said key compartment by conditionally revealing a lock box access code.

29. The electronic lock box system as recited in claim 28, wherein a computer program stored in said first memory circuit may be updated when a predetermined data sequence is received at said first communications port from data stored on a portable memory device which indicates that following read data should be stored, and wherein new read data is then uploaded from said portable memory device and stored in said first memory circuit.

30. The electronic lock box system as recited in claim 28, wherein said predetermined data sequence contains a cryptographic check value tat allows said first processing circuit to verify that the following read data was not fabricated by an unauthorized source.

32. A method of operating an electronic lock box system, said method comprising:

providing a lock box with a secure compartment therein and a shackle for attachment to a fixed object;

providing a secure memory device;

providing a communications link used for exchanging data between said secure memory device and said lock box;

providing a portable computer that is capable of reading said secure memory device, said portable computer having a visual display device;

coupling said secure memory device and said lock box in such a way so as to permit communication between the secure memory device and the lock box through the communications link;

storing secure compartment access code data in said secure memory device through the communications link;

de-coupling said secure memory device from said lack box; and

coupling said secure memory device to said portable computer, reading said secure compartment access code data, and, by use of said visual display device of the portable computer, conditionally revealing said secure compartment access code data to a human user.