Authentication system

1. An authentication system for managing a plurality of physically unclonable function (‘PUF’) devices, the authentication system comprising:

an enrollment server configured to:

communicate challenges to the plurality of PUF devices;

receive, responsive to communicating a challenge to a respective PUF device, a commitment for subsequent authentication of the respective PUF device, the commitment including at least a blinded value, and a second first value, wherein the blinded value depends on a private value r exponentially, a random value, and unique physical properties of the respective PUF device, the blinded value defining a mapping for repeated generation of the private value r, and the first value depends on the private value r, and the random value;

communicate a verification request including the challenge, the blinded value, and a nonce to the respective PUF device, wherein the challenge and the blinded value are configured to enable repeated regeneration of the random value at the respective PUF device based on a repeatable key or secret generator;

receive an authentication token communicated from the respective PUF device, the authentication token generated at the respective PUF device based on the private value r and the nonce; and

verify the authentication token based on the at least part of the commitment for subsequent authentication.

2. The authentication system of claim 1 , wherein the enrollment server is configured to generate the random value.

3. The authentication system of claim 1 , wherein the enrollment server is configured to encrypt the random value with a key that is shared with the respective PUF device.

4. The authentication system of claim 1 , wherein the commitment includes an exponential function of the private value r.

5. The authentication system of claim 1 , wherein the blinded value encodes error correction information.

6. The authentication system of claim 1 , wherein the commitment includes an exponential function of the private value r and wherein the blinded value depends on a value of the exponential function.

7. The authentication system of claim 1 , wherein the enrollment server is further configured to select the random value as an element of a group of prime order.

8. The authentication system of claim 1 , wherein the enrollment server is configured to generate a limited verification set that includes the challenge and the authentication token.

9. The authentication system of claim 8 , wherein the limited verification set further includes an error-correction helper string, and the commitment includes a dependency upon the error-correction helper string.

10. The authentication system of claim 8 , further comprising an authentication server having the limited verification set; and

wherein the enrollment server is configured to communicate an authentication request through the authentication server, by triggering communication of the challenge, the blinded value, and a nonce to the respective PUF device by the authentication server.

11. The authentication system of claim 8 , wherein the enrollment server is configured to trigger communication of the verification request through a plurality of authentication servers each having a different limited verification set, wherein each limited verification set includes the challenge and a corresponding token that is specific to the particular authentication server.

12. The authentication system of claim 1 , wherein the enrollment server has a complete verification set that includes multiple different specific challenge values and the PUF device's corresponding commitment values.

13. The authentication system of claim 1 , wherein the enrollment server stores challenge values and corresponding commitment values for multiple PUF devices.

14. The authentication system of claim 1 , wherein the physical properties of the respective PUF device include a respective physically-unclonable function (‘PUF’) in the PUF device.

15. The authentication system of claim 14 , wherein the PUF of the PUF device is constructed and arranged in a field-programmable gate array.

16. The authentication system of claim 1 , further comprising a PUF device having a physically-unclonable function (‘PUF’) capable of generating an output O dependent on the physical properties of the respective PUF device.

17. The authentication system of claim 16 , wherein the PUF is constructed and arranged within a field-programmable gate array.

18. An authentication system for managing a plurality of PUF devices the authentication system comprising:

an enrollment server that stores a working verification set including:

a commitment received from a respective PUF device for subsequent authentication, the commitment including:

at least a blinded value, and a first value, wherein:

the blinded value depends on a private value r exponentially, a random value, and unique physical properties of the respective PUF device, the blinded value defining a mapping for repeated generation of the private value r; and

the first value depends on the private value r, and the random value; and

a challenge associated with the commitment, wherein the challenge and the blinded value are configured to enable repeated regeneration of the random value at the respective PUF device based on a repeatable key or secret generator; and

the enrollment server is configured to pre-process and convey data to the respective PUF device as part of a repeatable Boyko-Peinado-Venkatesan generation, and wherein the random value once regenerated can be processed as an input to the repeatable Boyko-Peinado-Venkatesan generation.

19. The authentication system of claim 18 , wherein the data includes exponents for a prime group.

20. The authentication system of claim 19 , wherein the data includes a group generator.

21. The authentication system of claim 18 , wherein the data includes an error-correction helper string, and wherein the commitment includes dependency upon the error-correction helper string.

22. The authentication system of claim 18 , further comprising an authentication server.

23. The authentication system of claim 18 , wherein the enrollment server is configured to pre-process and convey data to an authenticatable server as part of the repeatable Boyko-Peinado-Venkatesan generation.

24. The authentication system of claim 23 , wherein the data includes exponents for a prime group, and a group generator.

25. The authentication system of claim 18 , wherein the physical properties of the respective PUF device include a respective physically-unclonable function (‘PUF’) in the PUF device.

26. A physically-unclonable function (‘PUF) device for use with an authentication system, comprising:

an internal input and an internal output constructed and arranged so as to, in response to the internal input of a specific challenge C, generate an internal output O that is characteristic to the device and the specific challenge C;

a processor having a processor input that is connected to the internal output, the processor configured to:

in response to the receipt of an output O from the internal output triggered by a challenge, generate a commitment, the commitment including:

at least a blinded value, and a first value, wherein:

the blinded value depends upon a private value r exponentially, a random value, and physical properties of the respective PUF device, the blinded value defining a mapping for repeated generation of the private value r, and

the first value depends on the private value r, and the random value;

communicate the commitment to an enrollment server or authentication server;

in response to receipt of an authentication query that includes a nonce, the blinded value, and the challenge associated with the commitment, regenerate the random value to construct an authentication token that is based on the private value r and the nonce; and

communicate the authentication token for verification based on at least part of the commitment for subsequent authentication.

27. The PUF device of claim 26 , further comprising a physically-unclonable function (‘PUF’) having a PUF input and a PUF output, wherein the PUF input is the internal input and the PUF output is the internal output, and wherein the output O is characteristic to the PUF.

28. The PUF device of claim 27 , wherein the blinded value of the commitment includes an error-correction helper string.

29. The PUF device of claim 27 , further comprising a field-programmable gate array (‘FPGA’), wherein the PUF resides in the FPGA.

30. The PUF device of claim 29 , wherein the FPGA is part of a Spartan®-6 FPGA SP605 development board.