Abstract:
A method for controlling access to data contained within a radio frequency identification (RFID) tag associated with an item includes reading the RFID tag; receiving a first value from a personal communication device associated with a purchaser of the item; creating a key using the first value received from the personal communication device and a second value associated with the item; and initially transmitting the key to both the RFID tag and the personal communication device. The RFID tag is configured to automatically program one or more electrically programmable fuse devices therein so as to prevent subsequent reading of data therein by an RFID reading device, upon receipt of a valid key initially transmitted thereto. The RFID tag is further configured to automatically program one or more additional fuse devices therein so as to restore read access to the data therein, upon receipt of a valid key subsequently transmitted thereto.

Description:
BACKGROUND 
       [0001]    The present invention relates generally to radio frequency identification (RFID) technology, and, more particularly, to a method and system for protecting RFID tags on purchased goods. 
         [0002]    The use of radio frequency identification (RFID) devices in the retail industry has started to become wide spread as retailers have realized the potential of these small and inexpensive devices. An RFID tag, which can be placed onto a product offered for sale, can permit the retailer to automatically track movement of the product, perform automatic check-out of the customer (including instant debiting of the customer&#39;s account), automatic inventory control, locating misplaced product, and so forth. The use of such RFID devices can also provide the retailers with information regarding the customers themselves, such as their purchasing habits, their movement patterns through the retail store, and so on. 
         [0003]    RFID devices that are implanted onto products (commonly referred to as RFID tags) are typically powerless radios (although in some applications, the RFID tags can have an external power source, such as a battery for example) with a small amount of memory and perhaps a controller or a processor. The RFID tags receive power only when they are energized by RF signals from a RFID reader. In this type of device, a rectifier coupled to an antenna in the RFID tag converts energy in the RF signals into electrical energy to power the RFID tag. Once powered, the RFID tag can respond to probes from the RFID reader and thereafter provide information stored in its memory or execute instructions provided by the RFID reader. 
         [0004]    One problem associated with RFID tags on goods that are purchased by consumers is that once goods having RFID tags are removed from the store, the tags will the be able to be read by anyone possessing the right equipment. For instance, if a customer purchases items in a store and subsequently stores the purchased items in the truck of a car while continuing shopping, another person with an RFID reader can conceivably walk by the car and ascertain what items have been stored in the vehicle&#39;s trunk. This in turn, can provide a temptation for theft of such items. 
         [0005]    Accordingly, it would be desirable to device an effective way to disable the RFID tags so that they may not be read once the item containing the tag has left the store. Furthermore, it is also desirable to prevent unauthorized people from rendering the tags unreadable before the items have been purchased. On the other hand, it would also be desirable to be able to provide only the purchaser with the ability to one again render the RFID tag again readable in the event, for example, the purchaser wishes to return/exchange the purchased item. 
       SUMMARY 
       [0006]    The foregoing discussed drawbacks and deficiencies of the prior art are overcome or alleviated by, in an exemplary embodiment, a method for controlling access to data contained within a radio frequency identification (RFID) tag associated with an item, including reading the RFID tag; receiving a first value from a personal communication device associated with a purchaser of the item; creating a key using the first value received from the personal communication device and a second value associated with the item; and initially transmitting the key to both the RFID tag and the personal communication device. The RFID tag is configured to automatically program one or more electrically programmable fuse devices therein so as to prevent subsequent reading of data therein by an RFID reading device, upon successful receipt of a valid key initially transmitted thereto. The RFID tag is further configured to automatically program one or more additional fuse devices therein so as to restore read access to the data therein, upon successful receipt of a valid key subsequently transmitted thereto. 
         [0007]    In another embodiment, a method for disabling access to data contained within a radio frequency identification (RFID) tag associated with an item includes reading the RFID tag; receiving a first value from a personal communication device associated with a purchaser of the item; creating an encrypted key using the first value received from the personal communication device and a second value associated with the item; and initially transmitting the key to both the RFID tag and the personal communication device; wherein the RFID tag is configured to automatically program one or more electrically programmable fuse devices therein so as to prevent subsequent reading of data therein by an RFID reading device, upon receipt of a valid key initially transmitted thereto. 
         [0008]    In another embodiment, a method for restoring access to data contained within a disabled radio frequency identification (RFID) tag associated with an item includes selecting the disabled RFID tag from a list of one or more disabled RFID tags stored on a personal communication device; accessing an encrypted key stored on the personal communication device, the encrypted key associated with the selected disabled RFID tag; and transmitting the encrypted key to the disabled RFID tag; wherein the RFID tag is configured to automatically program one or more electrically programmable fuse devices therein so as to restore read access to the data therein upon a match between the encrypted key transmitted by the personal communication device and a stored key within the RFID tag. 
         [0009]    In still another embodiment, a system for selectively enabling and disabling access to data contained within a radio frequency identification (RFID) tag associated with an item an RFID reading device in communication with a point of sale (POS) computing device; the POS computing device configured to receive a first value sent from a personal communication device associated with a purchaser of the item, and to create a key using the first value received from the personal communication device and using a second value associated with the item; the POS computing device further configured to transmit the key to both the RFID tag and the personal communication device; wherein the RFID tag is configured to automatically program one or more electrically programmable fuse devices therein so as to prevent subsequent reading of data therein by an RFID reading device, upon receipt of a valid key initially transmitted thereto; and wherein the RFID tag is further configured to automatically program one or more additional fuse devices therein so as to restore read access to the data therein, upon receipt of a valid key subsequently transmitted thereto. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Referring to the exemplary drawings wherein like elements are numbered alike in the several Figures: 
           [0011]      FIG. 1  is a schematic diagram of an exemplary RFID system suitable for use in accordance with an embodiment of the invention; 
           [0012]      FIGS. 2(   a ) and  2 ( b ) are a flow diagram illustrating a method for implementing an encrypted disable operation for an RFID tag, in accordance with an embodiment of the invention; and 
           [0013]      FIGS. 3(   a ) and  3 ( b ) are a flow diagram illustrating a method for implementing a restore operation for the encrypted disable operation of  FIGS. 2(   a ) and  2 ( b ), in accordance with a further embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Disclosed herein is a method and system of selectively disabling and subsequently restoring the ability to read data stored on an RFID tag, wherein the tag is configured with a self-programmable fuse technology that makes and breaks electrical connections within the device. Although the disabling action renders the RFID tag unreadable, it does not destroy the data itself. Therefore, a purchaser of an RFID item has the additional capability of subsequently rendering the RFID tag readable again through successful implementation of a restore operation. 
         [0015]    Briefly stated, an encrypted “disable” key is sent to an RFID tag located on an RFID item at the time of purchase, wherein the key is a combination of values; one associated with the item itself, and another associated with a customer&#39;s personal communication device. This disable key is also sent to and stored within the user&#39;s device. If the portion of the disable key corresponding to the RFID item matches the value stored in the RFID tag, then a fuse is automatically blown in a portion of the RFID circuit used to store the information about the purchased item. 
         [0016]    This may be implemented using, for example, electrically programmable (eFuse) technology developed by IBM. This technology utilizes a combination of unique software algorithms and microscopic electrical fuses to help chips regulate and adapt to changing conditions and system demands by adjusting their circuitry. Particularly, an eFuse device may be programmed by passing a sufficient current through the structure such that its resistance is significantly altered from its initially fabricated state. 
         [0017]    The use of an encrypted disable value also protects the seller from a third party sending a rogue disable value to render the RFID tag unreadable prior to purchasing of the item containing the RFID tag. In addition, the exemplary system and method described hereinafter further provides the capability of restoring the readability of the RFID tag information in the event a valid item return/exchange is to take place. The customer uses the personal communication device to send the stored encrypted key information back to the RFID tag, wherein another electrically programmable fuse (or antifuse) device is blown (i.e., programmed) in another portion of the RFID circuit so as to once again provide access to the RFID data stored in the tag. 
         [0018]    Referring initially to  FIG. 1 , there is shown an exemplary RFID communication system  100  suitable for use in accordance with an embodiment of the invention. A person  102  (e.g., store customer) purchases at least one tagged item  104 , which in turn has at least one wireless or RFID tag  106  attached to the item  104 . The RFID tag  106  is capable of being interrogated by an RFID reader  108  which may be located at a point-of-sale (POS) terminal, the RFID reader  108  in communication with a POS computing device  110 . The POS computing device  110  may, for example, be configured to receive and process information read by the RFID reader  108 , and store the information in a database. In addition, the POS system may include a connection to a network  112 , which makes possible the exchange of information with other computing systems. It should be noted that although the RFID reader  108  and POS computing device  110  are depicted as separate devices, the functions thereof could also be integrated within a single computing device. 
         [0019]    As further illustrated in  FIG. 1 , the customer  102  possesses a personal communication device  114  which may be, for example, a cellular phone or personal digital assistant (PDA) capable of wireless communication. As described in greater detail below, various wireless communication paths  116  are depicted in  FIG. 1  to represent possible communication paths between the RFID tag  106 , the RFID reader  108 , the POS computing device  110  and the customer&#39;s personal communication device  114 . 
         [0020]    Referring now to  FIGS. 2(   a ) and  2 ( b ), there is shown a flow diagram illustrating a method  200  for implementing an encrypted disable operation for an RFID tag, in accordance with an embodiment of the invention. As specifically illustrated in block  202  of  FIG. 2(   a ), the method  200  is initiated by reading the item  104  using the RFID reader  108 . If at decision block  204  it is determined that the item  104  does not have an RFID tag  106  associated therewith, the disable process goes no further. On the other hand, if the item  104  does include an RFID tag  106 , then the method  200  proceeds block  206 , wherein the POS computing device  110  receives a first unique value sent from the customer&#39;s personal communication device  114 . 
         [0021]    This first unique value is used by the POS computing device  110  recording the sale to create an encrypted key that consists of two parts. The first part of the key is a second unique value corresponding to the RFID item  104  to be purchased, which may retrieved from a database by the computer registering the sale. The second part the encrypted key is the first unique value received from the purchaser&#39;s personal communication device  114 . In an exemplary embodiment, the POS computing device  110  concatenates the two unique values and encrypts them to create the key, as shown in block  208 . Then, in block  210 , the encrypted key is sent from the POS computing device  110  to both the customer&#39;s personal communication device  114  and the RFID tag  106 . 
         [0022]    Referring specifically now to  FIG. 2(   b ), the method  200  proceeds to block  212 , wherein the RFID tag  106  then decrypts the key and compares the first part of the decrypted concatenated value received from the POS computing device  110  to a stored value therein. If, at decision block  214 , the first part of the key (i.e., the second unique value corresponding to the particular RFID item  104 ) does not match the value stored in the RFID tag  106 , the process exits with no further action. This feature prevents the unintended disabling of other RFID tags that may be within the communication range of the POS computing device  110 . 
         [0023]    On the other hand, if there is a match, then the combined concatenated value will be stored in the RFID tag  106 , and software stored within the tag  106  will the initiate the programmable fuse technology (e.g., eFuse) associated therewith to disable the RFID tag so as to render the data therein unreadable by any RFID reading device, as shown in block  216 . For example, the RFID tag software may initiate a self-reprogramming sequence in which one or more fuses within in the tag  106  are blown so as to cut off access to the data stored therein. However, the data itself is not erased or destroyed by this process. Finally, decision block  218  reflects whether there are additional RFID items to be read and disabled. If not, the process ends at that point; otherwise, the method returns back to block  202  in  FIG. 2(   a ) to read another item. 
         [0024]    As indicated above, the disabling of the RFID tag  106  during a purchase transaction prevents unauthorized reading of the tag data by a third party possessing RFID reading equipment. However, as also indicated above, it may become desirable (at the purchaser&#39;s discretion) to render the RFID tag  106  readable again. Thus,  FIGS. 3(   a ) and  3 ( b ) are a flow diagram illustrating a method  300  for implementing a restore operation for an RFID item that has been previously disabled according to the process of  FIGS. 2(   a ) and  2 ( b ), in accordance with a further embodiment of the invention. 
         [0025]    As specifically shown in  FIG. 3(   a ), the method  300  begins at block  302 , wherein the customer  102  uses the personal communication device  114  to access a list of RFID items that have been purchased and the tags disabled in accordance with the process described above. If at decision block  304  it is determined that the purchaser  102  does not wish to restore the readability of any disabled RFID tags, then the restore process goes no further. On the other hand, if it is desired to restore the readability of at least one RFID tag  106 , then the method  300  proceeds block  306 , where a specific RFID item is selected. Once selected, the encrypted key associated with the particular RFID tag  106  is accessed by the personal communication device  114 , as shown in block  308 . It will be recalled that during the disable routine, the encrypted key sent by the POS computing device  110  is stored in both the RFID tag  106  and the personal communication device  114 . Then, as shown in block  310 , the customer  102  uses the personal communication device  114  to send the encrypted key to the RFID tag  106  to be restored. 
         [0026]    Referring specifically now to  FIG. 3(   b ), the method  300  proceeds to block  312 , wherein the RFID tag  106  then decrypts the key sent from the customer&#39;s personal communication device  114  and compares this key to the one stored therein. Once again, the key represents the combination (concatenation) of a second unique value corresponding to the RFID item  104  and a first unique value originally sent from the customer&#39;s personal communication device  114 . If, at decision block  314 , the key sent from the customer&#39;s personal communication device  114  does not match the key stored in the RFID tag  106 , the process exits with no further action. 
         [0027]    However, if a match does exist, then the process  300  proceeds to block  316  where the readability is automatically restored by the RFID tag  106 . In the exemplary embodiment of eFuse technology described above, this may be accomplished through software initiated blowing of an additional fuse(s) or antifuse(s) within the tag  106  that restores access to the RFID data. Finally, decision block  318  reflects whether there are additional RFID items to be restored. If not, the process ends at that point; otherwise, the method returns back to block  302  in  FIG. 3(   a ) to access the list of other disabled RFID items. 
         [0028]    In view of the above, the present method embodiments may therefore take the form of computer or controller implemented processes and apparatuses for practicing those processes. The disclosure can also be embodied in the form of computer program code containing instructions embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other computer-readable storage medium, wherein, when the computer program code is loaded into and executed by a computer or controller, the computer becomes an apparatus for practicing the invention. 
         [0029]    While the invention has been described with reference to a preferred embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.