Patent ID: 8593252
Filing Date: 2013-11-26
Classification: G07C

Abstract:
1. A method for operating an electronic lock box system, said method comprising: (a) providing an electronic lock box having a first processing circuit, a first memory circuit, a first short range wireless communications device, a secure compartment having a movable opening element that is under the control of said first processing circuit, and a first data input device: (i) periodically inspecting said first data input device to determine if it has been activated, and if so, determining a first input data value that is entered thereon by a user; (ii) retrieving data stored in said first memory circuit, including a unique to lockbox identifier value; (iii) constructing a hail message from said unique lockbox identifier value and from said first input data value, and transmitting said hail message using said first short range wireless communications device; and (b) providing a portable transponder having a second processing circuit, a second memory circuit, and a second short range wireless communications device: (i) retrieving data stored in said second memory circuit, including a user identifier data value; and (ii) determining if said second short range wireless communications device has received said hail message from said electronic lock box; and if so, based upon said user identifier data value, determining if said hail message contains information corresponding to the identity of said user; (c) if said received hail message corresponds to the identity of said user, then at said portable transponder: (i) retrieving data stored in said second memory circuit, including a second time sensitive encryption key value; (ii) executing a second data encryption routine that uses said second time sensitive encryption key value and applies it to said user identifier data value, thereby creating a second encrypted data message; (iii) transmitting a response message that includes said second encrypted data message, using said second short range wireless communications device; and (d) at said electronic lock box: (i) determining if said first short range wireless communications device has received said response message from said portable transponder, and if so: (ii) retrieving data stored in said first memory circuit, including a first time sensitive encryption key value; (iii) executing a first data decryption routine that uses said first time sensitive encryption key value and applies it to said response message, thereby generating a first identifier code value; and (iv) comparing said first identifier code value to said first input data value, and if there is a match, then granting access to said secure compartment of the electronic lock box.