Low Cost RFID Tag Security And Privacy System And Method

• US 20080297326A1
• Filed: 03/25/2008
• Published: 12/04/2008
• Est. Priority Date: 03/30/2007
• Status: Abandoned Application

• Current Assignee: GSI Group Corporation (Novanta Inc.)
• Original Assignee: SkyeTek, Inc. (RFID Holdings, Inc.)
• Inventors: Chakraborty, Sayan, Bruns, Logan, Shah, Vikram
• Application Number:
  US12/055,265
• Publication Number:
  US 20080297326A1
• Time in Patent Office: Days
• US Class Current: 340/10.52
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32

Abstract

A method for provisioning security for an RFID tag. Initially, a random new tag ID is generated, and a new master key is generated based on an existing master key. Encrypted user data to be placed on the tag is generated utilizing the new tag ID as an IV and the new master key as input to an encryption algorithm. The new tag ID and the encrypted user data are then written to the tag.

Claims

1. A method for provisioning security for an RFID tag comprising:

generating a random new tag ID;

generating a new master key based on an existing master key; and

generating encrypted user data to be placed on the tag utilizing the new tag ID as an IV and the new master key as input to an encryption algorithm; and

writing the new tag ID and the encrypted user data to the tag.

2. The method of claim 1, further including:

writing a symmetric signature of the encrypted user data to the tag.

3. The method of claim 1, wherein a present tag ID read from a protected RFID tag is correlated with a previous tag ID owned by the same tag, by storing one or more of the previous tag IDs in encrypted form in the tag on each rewrite operation performed on the tag.

4. The method of claim 1, further including:

generating a hash code for each instance of the tag ID; and

correlating a present tag ID, read from a protected RFID tag, with a previous tag ID owned by the same tag, by storing one at least one said hash code in encrypted form in memory of the tag on each rewrite operation performed on the tag.

5. A method for provisioning security for an RFID tag comprising:

generating a random tag ID based on a known fixed-value tag ID;

generating a new master key based on an existing master key;

encrypting user data to be placed on the tag utilizing the tag ID as an IV and the new master key as input to an encryption algorithm;

generating a keyed symmetric signature of the user data utilizing the tag ID as an IV, the new master key, and clear text user data as input to a keyed hashing algorithm;

writing the tag ID, the encrypted user data, and the symmetric signature to appropriate parts of the tag; and

generating one or more passwords based on the tag ID as an IV and the new master key as input to a keyed hashing algorithm; and

locking data fields in the tag using the passwords.

6. The method of claim 5, wherein a present tag ID read from a protected RFID tag is correlated with a previous tag ID owned by the same tag, by storing one or more of the previous tag IDs in encrypted form in the tag on each rewrite operation performed on the tag.

7. The method of claim 5, further including:

generating a hash code for each instance of the tag ID; and

correlating a present tag ID, read from a protected RFID tag, with a previous tag ID owned by the same tag, by storing one at least one said hash code in encrypted form in memory of the tag on each rewrite operation performed on the tag.

8. A method for enforcing security for an RFID tag having a tag ID and an associated master key used for provisioning the tag, the method comprising:

reading the tag ID from the tag;

generating a keyed symmetric signature of the user data utilizing the tag ID as an IV, the master key, and clear text user data as input to a keyed hashing algorithm;

decrypting the user data read off the tag utilizing the tag ID as an IV and the master key as input to an encryption algorithm;

generating a keyed symmetric signature of the decrypted user data utilizing the tag ID as an IV, the master key, and clear text user data as input to a keyed hashing algorithm;

reading the symmetric signature from the tag; and

comparing the keyed symmetric signature to the symmetric signature read from the tag to determine validity of the tag.

9. The method of claim 8, further including reading data fields, in the user data, from the tag, including encrypted user data and the symmetric signature.

10. The method of claim 8, further including:

generating a password for locking and unlocking access to user data stored on the tag, based on the tag ID as an IV and the master key as input to a keyed hashing algorithm.

11. The method of claim 10, further including:

locking and unlocking the data fields of the tag with the generated passwords.

12. A method for preventing tracking an RFID tag including a tag ID and an associated existing master key used for provisioning the tag, the method comprising:

reading the present tag ID from the tag;

reading data fields, in the user data, from the tag including encrypted user data and an optional symmetric signature;

generating a new tag ID for the tag; and

re-provisioning the tag utilizing the new tag ID by;

generating a new master key based on the existing master key;

encrypting user data to be placed on the tag utilizing the new tag ID as an IV and the new master key as input to an encryption algorithm; and

writing the new tag ID, the encrypted user data, and the optional symmetric signature to the tag.

13. A method for correlating a present tag ID, read from a protected RFID tag, with a previous tag ID owned by the same RFID tag comprising:

storing one or more of the previous tag IDs in encrypted form in memory of the tag on each rewrite operation performed on the tag.

14. The method of claim 13, further including:

generating a hash code for each instance of the tag ID; and

correlating a present tag ID, read from the protected RFID tag, with the previous tag ID by storing one at least one hash code in encrypted form in memory of the tag on each rewrite operation performed on the tag.