Method and device for protecting products against counterfeiting
View Patent ↗A method for protecting a product against counterfeiting is provided that has a transponder associated with the product, upon which at least one unique identifier is stored, wherein a flag in a set or cleared state is associated with the identifier, and when the flag is set, read access to the identifier by a reader is only permitted after authentication. The invention further relates to a transponder for protecting a product against counterfeiting.
1. A method comprising:
receiving a request to access a first unique identifier stored in a shadow memory area of a transponder, read access to the first identifier being based on a state of a flag and on knowledge of secret shadow memory access information, the transponder having a second unique identifier stored in a second memory area;
requiring authentication prior to permitting read access to the first identifier in response to the state of the flag having a first value; and
permitting read access to the first identifier when the request includes the secret shadow memory access information.
2. The method of claim 1 further comprising preventing overwriting the state of the flag by writing the flag in a non-reprogrammable memory area.
3. The method of claim 1 further comprising analyzing a bit of the first identifier used to emulate the state of the flag.
4. The method of claim 3 , wherein analyzing at least one bit of the first identifier comprises combining the bit of the at least one unique identifier with a clock signal.
5. The method of claim 1 further comprising detecting manipulation of the first identifier through a state of a check digit associated with the identifier.
6. The method of claim 1 wherein the first identifier stored in the shadow memory area is encrypted.
7. The method of claim 1 further comprising constructing a portion of the second identifier using the first identifier.
8. The method of claim 1 , wherein the secret shadow memory access information comprises one or more of:
a secret memory address; and
a secret access command.
9. The method of claim 1 , further comprising:
receiving a request to access the second unique identifier stored in the second memory area of the transponder, read access to the second identifier being based on the state of the flag; and
requiring authentication prior to permitting read access to the second identifier in response to the state of the flag having a first value.
10. A transponder comprising:
a shadow memory area storing a first unique identifier, read access to the first identifier being based on a state of a flag and on knowledge of secret shadow memory access information;
a second memory area storing a second unique identifier; and
one or more computer-readable non-transitory storage media coupled to the memory areas that embody logic that is operable when executed to:
receive a request to access the first identifier stored in the shadow memory area;
require authentication prior to permitting read access to the first identifier in response to the state of the flag having a first value; and
permit read access to the first identifier when the request includes the secret shadow memory access information.
11. The transponder of claim 10 , wherein the logic is further operable to prevent overwriting of the state of the flag by writing the flag in a non-reprogrammable memory area.
12. The transponder of claim 10 , wherein the logic is further operable to analyze a bit of the first identifier used to emulate the state of the flag.
13. The transponder of claim 12 , wherein the logic to analyze at least one bit of the first identifier is further operable to combine the bit of the at least one unique identifier with a clock signal.
14. The transponder of claim 10 , wherein the logic is further operable to detect manipulation of the first identifier-through a state of a check digit associated with the at least one unique identifier.
15. The transponder of claim 10 , wherein the first identifier stored in the shadow memory area is encrypted.
16. The transponder of claim 10 , wherein a portion of the second identifier is constructed using the first identifier.
17. The transponder of claim 10 , wherein the secret shadow memory access information comprises one or more of:
a secret memory address; and
a secret access command.
18. The transponder of claim 10 , wherein the logic is further operable to:
receive a request to access the second unique identifier stored in the second memory area of the transponder, read access to the second identifier being based on the state of the flag; and
require authentication prior to permitting read access to the second identifier in response to the state of the flag having a first value.
19. One or more non-transitory computer-readable storage media that embody logic that is operable when executed to:
receive a request to access a first unique identifier stored in a shadow memory area of a transponder, read access to the at least one unique identifier being based on a state of a flag and on knowledge of secret shadow memory access information, the transponder having a second unique identifier stored in a second memory area;
require authentication prior to permitting read access to the first identifier in response to the state of the flag having a first value; and
permit read access to the first identifier when the request includes the secret shadow memory access information.
20. The one or more non-transitory computer-readable storage media of claim 19 wherein the logic when executed is further operable to prevent overwriting the state of the flag by writing the flag in a non-reprogrammable memory area.
21. The one or more non-transitory computer-readable storage media of claim 19 , wherein the logic when executed is further operable to analyze a bit of the first identifier used to emulate the state of the flag.
22. The one or more non-transitory computer-readable storage media of claim 21 , wherein analyzing at least one bit of the first identifier further comprises combining the at least one bit of the first identifier with a clock signal.
23. The one or more non-transitory computer-readable storage media of claim 19 , wherein the logic when executed is further operable to detect manipulation of the first identifier through a state of a check digit associated with the first identifier.
24. The one or more non-transitory computer-readable storage media of claim 19 , wherein the first identifier stored in the shadow memory area is encrypted.
25. The one or more non-transitory computer-readable storage media of claim 19 , wherein a portion of the second identifier is constructed using the first identifier.
26. The one or more non-transitory computer readable storage media of claim 19 , wherein the secret shadow memory access information comprises one or more of:
a secret memory address; and
a secret access command.
27. The one or more non-transitory computer-readable storage media of claim 19 , wherein the logic when executed is further operable to:
receive a request to access the second unique identifier stored in the second memory area of the transponder, read access to the second identifier being based on the state of the flag; and
require authentication prior to permitting read access to the second identifier in response to the state of the flag having a first value.