Electronic lock system and method for its use

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.

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.

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.

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.

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.

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.

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.