Patent Application
20100134287
The present invention relates generally to a method of detecting a counterfeit RFID tag and, more particularly, a method of detection that does not require use of an external database for RFID tag verification or authentication.
The use of RFID tags in commercial applications is of increasing importance. Such tags are incorporated into sundry products for the purpose of product identification as well as tracking a product from manufacture through ultimate end use. An RFID tag is typically manufactured by an electronics manufacturer for subsequent incorporation into an object by the manufacturer of that object. A product identification code is typically incorporated into the tag by the manufacturer of a product and the tag is affixed to the product throughout the life of the product. The RFID tag thus contains data identifying the product into which it is incorporated that is accessible to an external reader. The stored data may include an identification of the tag as well as the product into which it is incorporated.
It is an increasing problem for RFID tags associated with an object to be fraudulently removed or replaced by counterfeit tags in order to circumvent identification by reader systems. For example, an RFID tag may be incorporated into a commercial trailer tire and tracked as the trailer is transported from location to location. The tag may contain data identifying the tire to the trailer and load so that the transporter can ensure that the tires originally placed on the trailer remain so placed. Other types of information may be stored into the RFID tag memory data base and externally accessed by a reader such as the load being transported and the tractor utilized in conjunction with the trailer. A fraudulent replacement of the tires on the trailer may go undetected if the RFID tag is replaced by a counterfeit and the counterfeit is programmed to have the product identification data. It is accordingly a desire of the industry to have the means to detect whether a given RFID tag is counterfeit. Such a method should be capable of field application without requiring recourse to information or data from a database.
According to an aspect of the invention, a method for determining a counterfeit from authentic RFID tag includes: assigning a unique tag identification number T wherein T=tag identification number TID; locking the unique number T into tag memory; assigning a secondary unique number E wherein E=a unique electronic product code EPC; locking the unique number E into tag memory; deriving a kill password K calculated based on an encryption algorithm f wherein K=f(T,E); locking the kill password K into tag memory; reading from the tag T′=TID; E′=EPC; and K′=kill password; calculating an expected kill password Ke based on the same encryption algorithm f wherein Ke=f(T′,E′); comparing Ke to K′; concluding the tag is suspected counterfeit if Ke does not equal K′. It may further be concluded that the tag is authentic should the comparison result in Ke equaling K′.
In another aspect, the assignment and locking of TID and EPC are conducted by separate first and second parties. Assignment and locking of TID may be effected by a party such as the tag source and assignment and locking of the EPC and/or the kill password may be effected by a second party such as the source of an object into which the tag is incorporated.
The invention will be described by way of example and with reference to the accompanying drawings in which:
Referring initially to
The RFID tag 10 may be programmed with data including a tag identification number using the station depicted in
As shown in
With reference to
The transponder device or RFID tag 10 is of a type common within the industry and commercially available. The device combines data storage and transmission capability initiated by receipt of RF signal. Upon activation, the transponder transmits an RF data stream to a remote RF receiver. The stored data may include pertinent information that a user would find beneficial to monitor in the operation of a vehicle or a commercial fleet, such as an identification of the vehicle, the tire, the wheel unit, and/or the cargo conveyed by the vehicle and its destination. The RF transponder may be read-only or may include read-write capability. Because a proper identification of the tire/trailer/tractor and its cargo may utilize the data stored within the device 10, it is important that the integrity of the device 10 and data stored therein be established and maintained. A fraudulent or inadvertent replacement of an authentic tag 10 with a counterfeit tag may have costly consequences in applications where the tag data is utilized to ensure a proper identification of the object to which the tag attaches.
Data from the wheel unit transponder(s) 10 are received by antenna device(s) 40 that are located within a read station and relayed by connections 42 to an RF transceiver 44 connected by data transmission lines 46 to a data processing computer 48. A display of information from the RFID tag 10 to a user is thereby facilitated.
It will be appreciated that the read station 36 may be utilized in a commercial trucking operation to monitor and identify a tractor 50 and a trailer 52 as shown in
The method disclosed herein is for detecting that a given RFID tag is counterfeit and uses only information on the tag without recourse or need for accessing a database. The methodology requires one field (memory area) of the tag to have been uniquely written to and permanently locked into tag memory by the RFID chip manufacturer. The encoding of the chip by the RFID manufacturer to include a unique number identifying the chip is referred to at 54 in
It will be appreciated that the aforementioned assignment and locking of the TID and E into tag memory is done by two separate entities or parties; typically but not necessarily the chip manufacturer (TID) and the object manufacturer (E). The two unique numbers, each assigned and locked into memory by an unrelated separate party, are then employed by means of an encryption algorithm to calculate a Kill Password K. In allocating responsibility for the assignment and locking of two unique numbers TID and E to two unrelated entities or parties, the resultant generated Kill Password K is not only unique but also incapable of reconstruction from the knowledge of one but not both unique numbers TID and E.
The decoding process as shown in
TAG B represents a counterfeit tag. The data read from the TAG B reveals a copied EPC and a copied kill-pwd number. However, the TID number cannot be copied and the TID for the TAG B accordingly differs from TAG A. If the tag were genuine, the kill password should be Ke=f(0×1871766A, 0×9233B5F6)=0×7772F93D which does not equal the copied kill_pwd K′=0×4E872639. Therefore, the tag is suspect. Conversely, if the kill passwords were the same, the authenticity of the tag would be shown. Other encryption algorithms may be utilized if desired. The use of multiple identification numbers assigned by different parties, the generation of a kill password as a function of a number TID that cannot be copied, allows for the detection of a fraudulent tag that generates a kill password that does not equate.
Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims.
