Abstract:
A method of interrogating an RFID label utilises an RFID interrogation system operable by a vendor. The method comprises the steps of: transmitting an interrogation signal which is receivable by RFID labels within an area so as to interrogate any RFID labels in that area. An intelligible return signal from the RFID label is only received when the RFID label was issued by the same vendor.

Description:
[0001]     The present invention relates to radio frequency identification (RFID) systems, and more specifically to a method of ensuring the confidentiality of a customer once he or she brings an RFID label out of the store from where the item to which the label is attached was first purchased.  
       BACKGROUND OF THE INVENTION  
       [0002]     RFID technology provides an alternative to bar code reader technology for distinguishing and recording items for purchase. RFID may result in labour savings to retailers, since it may make obsolete conventional methods of identifying products.  
         [0003]     Some of the uses of RFID technology are disclosed in U.S. Pat. No. 6,019,394 assigned to the assignee of the present invention. This patent is hereby incorporated by reference.  
         [0004]     RFID labels may be permanently attached to products. RFID labels permanently attached to clothing and other items may be worn or carried by customers into stores long after they were originally purchased. These RFID labels may be detected by RFID interrogators within stores or other locations regardless of whether or not the owners of those interrogators have any right to access the information on those labels.  
         [0005]     Due to the increasing near ubiquitous spread of RFID labels and scanning systems, privacy groups such as CASPIAN (Consumers Against Supermarket Privacy Invasion) have begun heralding RFID as spy chips and have raised consumer concern over potential privacy implications of the technology. Most of the concern involves item level tagging.  
         [0006]     Therefore, it would be desirable to help alleviate consumer concern if it were possible to prevent unauthorised interrogation of RFID tags, whilst still maintaining their usefulness, for example, when returning unwanted or malfunctioning purchases to a store.  
       SUMMARY OF THE INVENTION  
       [0007]     It is accordingly an object of the present invention to provide system for and a method of detecting and managing RFID labels on items carried by a customer which ameliorates the aforementioned problems.  
         [0008]     It is a second object of the present invention to provide an RFID label which ameliorates the aforementioned problems.  
         [0009]     According to a first aspect of the present invention there is provided a method of interrogating an RFID label, utilising an RFID interrogation system operable by a vendor, the method comprising the steps of: transmitting an interrogation signal which is receivable by RFID labels within an area so as to interrogate any RFID labels in that area; and  
         [0010]     only receiving an intelligible return signal from an RFID label when the RFID label was issued by the same vendor.  
         [0011]     Preferably, the returned data is encrypted. Most preferably, the method of encryption is chosen from the following: public key; private key; DES; Triple DES or RSA.  
         [0012]     Alternatively, the information includes only a reference number which can only be usefully interpreted by the vendor who issued the label.  
         [0013]     In a further alternative no signal is returned by the label if interrogated by an interrogator which is not part of the RFID system operated by the vendor who issued the label.  
         [0014]     Preferably the information includes customer specific information. Most preferably, the information includes information on the item which is purchased.  
         [0015]     Preferably, the area is a store or Mall.  
         [0016]     According to a second aspect of the present invention an RFID system including one or more RFID labels attached to one or more products, an RFID interrogator; and a computer which collates any information obtained from the one or more RFID labels, the one or more RFID labels being programmed such that access to information stored thereon can be gained only by an authorised RFID interrogator.  
         [0017]     Preferably, an authorised RFID interrogator is an RFID interrogator operated by the same vendor who issued the RFID label.  
         [0018]     According to a third aspect of the present invention there is provided an RFID label arranged such that access to information stored thereon can be gained only by an authorised RFID system.  
         [0019]     Preferably the authorised system is the system which is operated by the vendor who issued the label.  
         [0020]     In one embodiment data thereon is encrypted. Most preferably, the method of encryption is chosen from the following: public key; private key; DES; Triple DES or RSA.  
         [0021]     Alternatively, the information includes only a reference number which can only be usefully interpreted by the vendor who issued the label.  
         [0022]     In a further embodiment no signal is returned by the label if interrogated by an interrogator which is not part of the RFID system operated by the vendor who issued the label. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]     Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings, in which:  
         [0024]      FIG. 1  is a block diagram of a transaction processing system; and  
         [0025]      FIG. 2  is a flow diagram illustrating the method of operation of the system of  FIG. 1  in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]     Referring now to  FIG. 1 , transaction system  10  primarily includes RFID label interrogator  14 , terminal  16 , and server  18 . This system can at present be used, as described below, to read an RFID label on a customer&#39;s purchases from a first store as the customer walks, for example, through a Mall or a second unrelated store.  
         [0027]     In the latter example an in-store RFID interrogator  14  emits a signal and receives return signals from nearby store RFID labels  12  and customer RFID labels  26 . RFID interrogator  14  decodes the return signals and provides information from store RFID labels  12  and customer RFID labels  26  to terminal  16 .  
         [0028]     The RFID labels  12  and  26  store a serial number attached to the RFID tag, with all the details which are pertinent to the product and its purchase are stored on a server (either in store or on the web), in line with EPC Global standard for RFID. Alternatively, the RFID labels  12  and  26  can store label and product identification information and various amounts of additional information, such as date and time of purchase, location of purchase, and seller. The additional information is stored at checkout.  
         [0029]     Terminal  16  uses RFID interrogator  14  to read store RFID labels  12  and customer RFID labels  26 . Terminal  16  may include a checkout transaction terminal, a return station computer, or a kiosk computer.  
         [0030]     Terminal  16  executes RFID label processing software  20 , which determines whether customer RFID label  26  is associated with an item from another store for which no purchase has been recorded within customer RFID label  26 . Identification information for store RFID labels  12  is stored in inventory data file  22 . If customer RFID label  26  contains store information for a different store but fails to contain purchase information, then the associated item may be considered stolen, for example.  
         [0031]     If customer RFID label  26  contains purchase information from the other store, then RFID label processing software  20  may additionally deliver promotions based upon detected item information in customer RFID label  26  using promotion data file  24 .  
         [0032]     Transaction server  18  handles price and inventory requests from terminal  16 . Transaction server  18  also provides promotion information from promotion data file  24 .  
         [0033]     In  FIG. 2 , a method of operation of the RFID system  10  of  FIG. 1  in accordance with the present invention is illustrated in more detail beginning with START  40 .  
         [0034]     In step  42 , RFID interrogator  14  sends out a signal to interrogate any RFID labels in the vicinity. The signal may be sent in response to an operator command or trigger or by a signal from a proximity sensor, similar to barcode readers.  
         [0035]     If terminal  16  is a checkout station computer, then RFID interrogator  14  interrogates store RFID labels  12  on items to be purchased and customer RFID labels  26  on items carried or worn by the customer.  
         [0036]     If terminal  16  is a return station computer, then RFID interrogator  14  interrogates customer RFID labels  26  on items to be returned and customer RFID labels  26  on other items carried or worn by the customer.  
         [0037]     If terminal  16  is a kiosk, then RFID interrogator  14  interrogates store RFID labels  12  on items presented by the customer for price check and customer RFID labels  26  on items carried or worn by the customer.  
         [0038]     In prior art systems, as illustrated instep  44 , RFID interrogator  14  receives return signals from store RFID labels  12  and customer RFID labels  26 . Thereafter, in step  46 , RFID interrogator  14  decodes the information from store RFID labels  12  and customer RFID labels  26  (regardless of the store from whence the label originated) and sends the decoded information to terminal  16 .  
         [0039]     That information may only be a serial number stored in the RFID labels  12  and  26 , with all the details which are pertinent to the product and its purchase being stored on a server (either in store or on the web), in line with EPC Global standard for RFID. Alternatively, the information may include product identification information and various amounts of additional information, such as date and time of purchase, location of purchase, and seller.  
         [0040]     This allows information to be obtained by users of the RFID system who do not have any right to that information.  
         [0041]     However, in accordance with the present invention, after the RFID interrogator  14  sends out a signal to interrogate any RFID labels in the vicinity, step  42 , either no return signal is transmitted or the return signal is encrypted or the return signal is a vendor specific code, such as a retailer&#39;s transaction number or a receipt number information which is meaningless to the operators of the RFID interrogator in question, step  48 , as the number could only be coupled to secure information by the vendor.  
         [0042]     If no signal is transmitted that is because the label is arranged to transmit only after receipt of a specific interrogation signal, perhaps including a public key. If no such signal is received then the label is not prompted to transmit information to the interrogator. Alternatively, the label may always send information, but that information will be encrypted such that it can not be read by unauthorised users or it may be an un-encrypted but vendor specific reference number as described above. If encryption is utilised any of a number of standard systems may be employed, including, but not limited to, public key or private key encryption process. DES, Triple DES, RSA.  
         [0043]     Although the present invention has been described with particular reference to certain preferred embodiments thereof, variations and modifications of the present invention can be effected within the spirit and scope of the following claims.