Tag authentication apparatus and method for radio frequency identification system

• US 20070133807A1
• Filed: 11/30/2006
• Published: 06/14/2007
• Est. Priority Date: 12/12/2005
• Status: Abandoned Application

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Hong, Do, Kim, Ho, Lee, Hang
• Application Number:
  US11/607,496
• Publication Number:
  US 20070133807A1
• Time in Patent Office: Days
• US Class Current: 380/282
• CPC Class Codes: H04L 2209/805 Lightweight hardware, e.g. radio-frequency identification [RFID] or sensor
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04L 9/50 using hash chains, e.g. blockchains or hash trees

Abstract

A radio frequency identification (RFID) tag authentication apparatus and method for accomplishing quick authentication and solving privacy problems using a hash algorithm are provided. An RFID tag includes a memory unit storing a tag'"'"'s secret information and a group'"'"'s secret information and a hash chain computation unit encrypting secret information based on a hash algorithm. The tag authentication apparatus includes a DB storing information about RFID tags, which is classified into groups and includes each group'"'"'s secret information and each tag'"'"'s secret information; a group'"'"'s secret information search unit finding a group to which a tag to be authenticated belongs; and a tag'"'"'s secret information search unit searching tags'"'"' secret information included in the found group.

Claims

1. A radio frequency identification (RFID) tag for an RFID system, the RFID tag comprising:

a memory unit storing a tag'"'"'s secret information, which is used to authenticate an RFID tag, and a group'"'"'s secret information, which is used to search for a group including the tag'"'"'s secret information; and

a hash chain computation unit encrypting the group'"'"'s secret information and the tag'"'"'s secret information based on a hash algorithm to obtain a conversion value.

2. The RFID tag of claim 1, wherein the group'"'"'s secret information and the tag'"'"'s secret information are updated by iteration of a hash chain when the RFID tag interacts with a reader that receives the conversion value.

3. The RFID tag of claim 1, wherein the group'"'"'s secret information and the tag'"'"'s secret information have a same hash chain count.

4. The RFID tag of claim 1, wherein the conversion value is a pair of a group'"'"'s secret information conversion value, which is obtained by performing an exclusive OR operation on a value of the group'"'"'s secret information before hash computation of the group'"'"'s secret information and a value of the group'"'"'s secret information after the hash computation, and a tag'"'"'s secret information conversion value, which is obtained by performing an exclusive OR operation on a value of the tag'"'"'s secret information before hash computation of the tag'"'"'s secret information and a value of the tag'"'"'s secret information after the hash computation.

5. A tag authentication apparatus for a radio frequency identification (RFID) system, the tag authentication apparatus comprising:

a DB storing information about RFID tags, which is classified into groups and includes each group'"'"'s secret information and each tag'"'"'s secret information;

a group'"'"'s secret information search unit generating a value by performing a hash chain on each group'"'"'s secret information stored in the DB using a hash algorithm and comparing the generated value with a received group'"'"'s secret information conversion value to find a group to which a tag needing authentication belongs; and

a tag'"'"'s secret information search unit generating a value by performing the hash chain on each tag'"'"'s secret information included in the group found by the group'"'"'s secret information search unit and comparing the value with a received tag'"'"'s secret information conversion value to find secret information of the tag, which needs authentication, in the DB.

6. The tag authentication apparatus of claim 5, wherein the classified information about each RFID tag is stored in a corresponding group in a form of a combination of a tag'"'"'s initial secret information, the tag'"'"'s secret information recently succeeding in authentication, a hash chain count corresponding to the recent successful authentication, and a tag'"'"'s ID information.

7. The tag authentication apparatus of claim 5, wherein the group'"'"'s secret information search unit limits the number of iterations of the hash chain by setting a threshold to be greater than a greatest hash chain count in a current group.

8. The tag authentication apparatus of claim 5, wherein the tag'"'"'s secret information search unit searches only information about RFID tags having a less hash chain count than a hash chain count at which the group'"'"'s secret information search unit finds the group to which the tag to be authenticated belongs.

9. The tag authentication apparatus of claim 5, wherein the tag'"'"'s secret information search unit performs search using each tag'"'"'s secret information recently succeeding in authentication and a hash chain count corresponding to the recent successful authentication.

10. A method of processing authentication information in a radio frequency identification (RFID) of an RFID system, the method comprising:

obtaining a conversion value by encrypting a tag'"'"'s secret information, which is used to authenticate an RFID tag, and a group'"'"'s secret information, which is used to search for a group including the tag'"'"'s secret information, using a hash chain, which is formed in the RFID tag to perform encryption based on a hash algorithm; and

updating the group'"'"'s secret information and the tag'"'"'s secret information in memory of the RFID tag.

11. The method of claim 10, wherein the group'"'"'s secret information and the tag'"'"'s secret information are updated by iteration of the hash chain when the RFID tag interacts with a reader that receives the conversion value.

12. The method of claim 10, wherein the group'"'"'s secret information and the tag'"'"'s secret information have a same hash chain count.

13. The method of claim 10, wherein the conversion value is a pair of a group'"'"'s secret information conversion value, which is obtained by performing an exclusive OR operation on a value of the group'"'"'s secret information before hash computation of the group'"'"'s secret information and a value of the group'"'"'s secret information after the hash computation, and a tag'"'"'s secret information conversion value, which is obtained by performing an exclusive OR operation on a value of the tag'"'"'s secret information before hash computation of the tag'"'"'s secret information and a value of the tag'"'"'s secret information after the hash computation.

19. A computer readable recording tag for recording a program for executing the method of any one of claims 10 through 18.

14. A tag authentication method for a radio frequency identification (RFID) system, the tag authentication method comprising:

classifying information about RFID tags, which includes each group'"'"'s secret information and each tag'"'"'s secret information, into groups and storing the classified information;

finding a group, to which a tag needing authentication belongs, by generating a value by performing a hash chain on each group'"'"'s secret information using a hash algorithm and comparing the generated value with a received group'"'"'s secret information conversion value; and

finding a tag'"'"'s secret information, needing authentication by generating a value by performing the hash chain on each tag'"'"'s secret information included in the found group and comparing the value with a received tag'"'"'s secret information conversion value.

15. The tag authentication method of claim 14, wherein the classified information about each RFID tag is stored in a corresponding group in a form of a combination of a tag'"'"'s initial secret information, the tag'"'"'s secret information recently succeeding in authentication, a hash chain count corresponding to the recent successful authentication, and a tag'"'"'s ID information.

16. The tag authentication method of claim 14, wherein the finding of the group'"'"'s secret information comprises limiting the number of iterations of the hash chain by setting a threshold to be greater than a greatest hash chain count in a current group.

17. The tag authentication method of claim 14, wherein the finding of the tag'"'"'s secret information comprises searching only information about RFID tags having a less hash chain count than a hash chain count at which the group to which the tag to be authenticated belongs has been found.

18. The tag authentication method of claim 14, wherein the finding of the tag'"'"'s secret information comprises perform the hash chain using each tag'"'"'s secret information recently succeeding in authentication and a hash chain count corresponding to the recent successful authentication.