A problem that can occur for product distribution is that of unauthorized copies of products. For example, a contract manufacture can receive the specifications for a product from a designer and make a number of authorized products. Unscrupulous manufacturers can then go on to make additional unauthorized, but identical, copies of the product to sell illegally at a high profit.
One way to get around this issue is by using a RFID tag that can encrypt and decrypt data. In this way, the integrity of products can be assured.
The problem with using present RFID tags to secure articles is that the cost of such RFID tags for authentication can be relatively large. This is because the present state of the art is to use tags with a large block of encrypted memory to describe the article, or to utilize an off line database to store attributes of the tagged article. In the former case the protocol for decrypting the stored information are complex and often require expensive and specially configured RFID readers, in the second case maintenance and upkeep of the database as well as insuring real time access have proven to be difficult logistical tasks.
Embodiments of the present invention include ways to use the less expensive RFID tags in an encryption and authentication scheme. Encryption and decryption can be done outside the RFID tag.
Embodiments of the present invention a permanent ID that RFID chip manufacturers typically put a on the RFID chip in combination with additional data that is provided by an authenticating authority (typically the legitimate manufacturer). Since this permanent ID is added in the chip manufacture process, it is impractical to spoof. The additional data is known to the authenticating authority and may be recovered from data written to the RFID tag memory.
The permanent ID and additional data, together the authentication data, can be encrypted then the encrypted value can be stored back onto another location on the RFID chip of the RFID tag. Validation can include decryption of the encrypted value and the comparing of the decrypted value with the authentication data.
A person who wanted to spoof the RFID tag would need to have access to the encryption algorithm. Merely copying data for a previous RFID chip would not be sufficient, since when decrypted, the decrypted version of the permanent ID would not match the permanent ID placed on the RFID chip by the RFID manufacturer.
One embodiment of the present invention, as shown in
The combination can be any type of combination including the permanent value and seed value. This can include operations such as addition, subtraction and multiplication, bit shifting, Boolean operations, bit reversal, padding, truncation etc.
The RFID tag can be authenticated by decrypting the encrypted values to obtain the permanent ID and the seed value.
The derived permanent ID obtained using the encrypted value can be compared to the permanent ID off of the RFID chip. The seed value determined from the encryption value can also be validated.
The RFID chip can also include product data.
The seed value can be obtained from a pool of seed values. In one embodiment, the writing of the encrypted value to the RFID chip can be done by an RFID reader, and this RFID reader can maintain the pool of seed values.
Public/private key encryption can be used. For the purpose of following discussion, the terms public and private keys are used for convenience. The system architect may choose to publish the “private” key and keep the “public” key secret. The encrypted value can encrypted with a public key. The encrypted value can then be decrypted by a private key. Alternately, any other encryption/decryption scheme can be used.
In step 204, the encrypted value is decrypted to get a combined value. In step 206, the combined value is analyzed to get a derived permanent ID and a derived seed value.
In step 208, using at least one of the derived permanent ID and the derived seed value to validate the RFID tag. The validation can include comparing the derived permanent ID portion obtained from the encrypted value with the permanent ID put on the RFID chip by the RFID manufacturer. The validation can include analyzing the derived seed value.
In one embodiment, the seed values are encrypted. The derived seed value can be decrypted to determine if the derived seed value is valid.
The encrypted values can be encrypted with a public key and the decryption uses a private key.
The method of
The RFID reader 402 can be configured through software to authenticate an RFID tag through the use of a public/private key encryption method. The public key can be stored on removable media. The stored public key can be encrypted or password protected such that the user must enter data in order to access the public key. The public key can be stored locally on the reader in re-writable memory, or non-re-writable memory.
Later, as shown in
The derived permanent ID can be compared to the permanent ID on the chip in step 508. If a spoofed value is used, then the derived permanent ID will not match the real permanent ID.
The derived seed 506 can be checked against remote or local database. Alternately, the derived seed value can be decrypted and then compared against a remote or local database.
The present system can prevent counterfeit product from getting into the supply chain and/or detect counterfeits at any of a number inspection point inside or outside of their control. RFID tags can be used to validate if a shipment is counterfeit at a customs inspection point or other locations. A potential rogue contract manufacturer (CM) can be prevented using the technology from producing electronically verifiable fakes.
Method can be as follows:
At customs or other location;
The designer can control the private key and agreed not share it with the contract manufacturer, thus they control the validation. Potentially the trusted partner could do this as a service. Even if the contract manufacturer knows the mathematical operation the designer controls the seed values which are traceable by manufacturer.
The date stamp can be useful either as a way to shift the public/private key sets or can be combined with the seed value (mathematically) at the time of encryption. This only becomes an issue if the private key becomes compromised.
The foregoing description of preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.
This application claims priority to U.S. Provisional Application No. 60/980,249 entitled “RFID TAG USING ENCRYPTED VALUE” by Robert R. Oberle, filed Oct. 16, 2007, which is hereby incorporated by reference [Atty. Docket No. RCDT-01022US0].
Number | Date | Country | |
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60980249 | Oct 2007 | US |