Secure authentication

• US 9,032,476 B2
• Filed: 05/12/2009
• Issued: 05/12/2015
• Est. Priority Date: 05/12/2009
• Status: Active Grant

• Current Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC), Regents of the University of California (University of California)
• Original Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC)
• Inventors: Potkonjak, Miodrag
• Primary Examiner(s): Choudhury, Azizul
• Assistant Examiner(s): FABBRI, ANTHONY E
• Application Number:
  US12/464,387
• Publication Number:
  US 20100293612A1
• Time in Patent Office: 2,191 Days
• US Class Current: 726/2
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06F 21/34 involving the use of external additional devices, e.g. dongles or smart cards
• CPC Class Codes: H01L 29/0669 Nanowires or nanotubes carbon nanotubes as material of solid-state device active part H10K85/211
• CPC Class Codes: H04L 63/0853 using an additional device, e.g. smartcard, SIM or a different communication terminal cryptographic mechanisms or cryptographic arrangements for entity authentication involving additional secure or trusted devices H04L9/3234
• CPC Class Codes: H04L 9/3278 using physically unclonable functions [PUF]

Abstract

Technologies are generally described for secure authentication tokens that employ hardware public physically unclonable functions. Each unique token can be implemented as hardware such that manufacturing variations provide measurable performance differences resulting in unique, unclonable devices or systems. For example, slight timing variations through a large number of logic gates may be used as a hardware public physically unclonable function of the authentication token. The authentication token can be characterized such that its physical characteristics may be publicly distributed to authenticators. Authenticators may then simulate the result from a particular input vector and then request the authentication token to generate the same result in a very short amount of time. The time may be specified such that the result could not be simulated by an imposter for a timely response.

Claims

1. An authentication token device, comprising:

a hardware public physically unclonable function that includes operational characteristics characterized by publicly available parameters, wherein the parameters are affected by unintentional manufacturing variability of the hardware public physically unclonable function;

an input register configured to load signals into the hardware public physically unclonable function at an input time, wherein the signals are propagated through the hardware public physically unclonable function so as to transform the signals in accordance with the unintentional manufacturing variability of the hardware public physically unclonable function; and

an output register configured to sample the transformed signals from the hardware public physically unclonable function at a specified time after the input time, wherein the transformed signals during the specified time differ from other transformed signals sampled at another time due to the unintentional manufacturing variability.

2. The authentication token device of claim 1, further comprising a timing mechanism configured to determine when to latch the transformed signals of the hardware public physically unclonable function into the output register.

3. The authentication token device of claim 1, further comprising an interface to a host computer, the interface coupled to the input register and the output register, wherein the interface is configured to provide the signals to the input register, and wherein the interface is configured to provide the the transformed signals to the host computer such that the host computer can validate the authentication token device based on the the transformed signals.

4. The authentication token device of claim 1, wherein the hardware public physically unclonable function operates within a time period less than a time period required to simulate the hardware public physically unclonable function from the operational characteristics.

5. The authentication token device of claim 1, wherein the hardware public physically unclonable function comprises a plurality of logic gates.

6. The authentication token device of claim 1, wherein the hardware public physically unclonable function comprises nanowires.

7. The authentication token device of claim 1, wherein the hardware public physically unclonable function comprises photonic crystals.

8. A method to generate an authentication challenge response using a hardware public physically unclonable function, the method comprising:

receiving initial values associated with the authentication challenge into an input register at an input time associated with the hardware public physically unclonable function, wherein the hardware public physically unclonable function is characterized by publicly available parameters that are affected by unintentional manufacturing variability of the hardware public physically unclonable function;

coupling logic signals corresponding to the initial values from the input register into the hardware public physically unclonable function;

propagating the logic signals through the hardware public physically unclonable function so as to transform the logic signals in accordance with unintentional manufacturing variability of the hardware public physically unclonable function; and

receiving a signal to latch the transformed logic signals from the hardware public physically unclonable function into an output register at a specified time after the input time, wherein the transformed logic signals latched during the specified time differ from other transformed logic signals latched at another time due to the unintentional manufacturing variability.

9. The method of claim 8, further comprising initializing the input register to a known state prior to receiving the initial values.

10. The method of claim 8, wherein the hardware public physically unclonable function generates a result within a time period less than a time period used to simulate the hardware public physically unclonable function to generate the result.

11. The method of claim 8, wherein the unintentional manufacturing variability of the hardware public physically unclonable function comprises unintentional manufacturing variability of a plurality of logic gates.

12. The method of claim 8, wherein the unintentional manufacturing variability of the hardware public physically unclonable function comprises unintentional manufacturing variability of nanowires.

13. The method of claim 8, wherein the unintentional manufacturing variability of the hardware public physically unclonable function comprises unintentional manufacturing variability of photonic crystals.

14. The method of claim 8, wherein the authentication challenge comprises a vector of initial values and a timing specification used in latching the transformed logic signals into the output register.

15. A non-transitory computer storage medium that includes computer-executable instructions stored thereon which, when executed by a computer system, cause the computer system to:

receive public information that characterizes unique parameters associated with a hardware public physically unclonable function;

formulate an authentication challenge to be posed to the hardware public physically unclonable function;

simulate the hardware public physically unclonable function based on the public information to generate an expected result to the authentication challenge, wherein the public information is associated with unintentional manufacturing variability of the hardware public physically unclonable function;

offer the authentication challenge to an authentication device comprising the hardware public physically unclonable function, wherein the expected result is obtained from the hardware public physically unclonable function at a specified time after an input time when signals are loaded into the hardware public physically unclonable function;

classify the authentication challenge as passed in response to receiving the expected result from the authentication device within a specified time period that is less than a time period required to simulate the hardware public physically unclonable function based on the public information to generate an expected result; and

classify the authentication challenge as failed in response to not receiving the expected result from the authentication device within the specified time period.

16. The computer storage medium of claim 15, wherein the authentication challenge comprises multiple result requests from the hardware public physically unclonable function.

17. The computer storage medium of claim 15, wherein the authentication challenge comprises a vector of initial values to load into the hardware public physically unclonable function and a timing specification used for latching to latch an output from the hardware public physically unclonable function.

18. The computer storage medium of claim 15, wherein the expected result comprises a set of results generated within a tolerance window of time.

19. The computer storage medium of claim 15, wherein the expected result comprises a statistical sample of a complete output vector.

20. The computer storage medium of claim 15, wherein the hardware public physically unclonable function comprises a plurality of logic gates.