DATA PROTECTION AND CRYPTOGRAPHIC FUNCTIONS USING A DEVICE-SPECIFIC VALUE

• US 20060271792A1
• Filed: 06/01/2006
• Published: 11/30/2006
• Est. Priority Date: 04/16/2002
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Devadas, Srinivas, Gassend, Blaise
• Granted Patent: US 7,818,569 B2
• Time in Patent Office: Days
• US Class Current: 713/189
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06F 21/72 in cryptographic circuits
• CPC Class Codes: G06F 21/73 by creating or determining hardware identification, e.g. serial numbers
• CPC Class Codes: G06F 21/77 in smart cards
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 21/86 Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2103 Challenge-response
• CPC Class Codes: G06F 2221/2121 Chip on media, e.g. a disk or tape with a chip embedded in its case
• CPC Class Codes: G06F 2221/2129 Authenticate client device independently of the user
• CPC Class Codes: G06F 2221/2153 Using hardware token as a secondary aspect
• CPC Class Codes: G06Q 20/3674 involving authentication
• CPC Class Codes: G09C 1/00 Apparatus or methods whereby a given sequence of signs, e.g. an intelligible text, is transformed into an unintelligible sequence of signs by transposing the signs or groups of signs or by replacing them by others according to a predetermined system cryptographic typewriters G09C3/00
• CPC Class Codes: H01L 2223/54433 containing identification or tracking information
• CPC Class Codes: H01L 2223/5444 for electrical read out
• CPC Class Codes: H01L 2223/54473 for use after dicing
• CPC Class Codes: H01L 23/544 Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps test patterns for characterising or monitoring manufacturing processes H01L22/00
• CPC Class Codes: H01L 23/576 using active circuits
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 2209/42 : Anonymization, e.g. involving pseudonyms
• CPC Class Codes: H04L 9/0897 : involving additional devices, e.g. trusted platform module [TPM], smartcard or USB
• CPC Class Codes: H04L 9/3278 : using physically unclonable functions [PUF]

Abstract

A digital value is generated in an integrated circuit such that the generated value substantially depends on circuit parameters that vary among like devices. The generated digital value is then used, for example, to access protected information in the device or to perform a cryptographic function in the integrated circuit.

Claims

1. A method comprising:

generating a digital value in an integrated circuit that substantially depends on circuit characteristics that vary among a plurality of like integrated circuits; and

using the generated digital value, including accessing protected information in the integrated circuit.

2. The method of claim 1 wherein the plurality of like integrated circuits includes integrated circuits fabricated according to a common design.

3. The method of claim 2 wherein the plurality of like integrated circuits includes integrated circuits fabricated according to a common lithography mask.

4. The method of claim 1 wherein the steps of generating the digital value and using the digital value are repeated without requiring storage of the digital value between repetitions.

5. The method of claim 1 wherein the protected information includes a key value.

6. The method of claim 1 wherein using the generated digital value includes determining cryptographic data using the digital value.

7. The method of claim 6 wherein determining the cryptographic data includes determining a key value.

8. The method of claim 7 wherein using the generated digital value includes using the determined key to decrypt the protected information.

9. The method of claim 1 wherein using the generated digital value further includes performing at least one of allowing an operation on the device, authenticating the device, decrypting data, and encrypting data.

10. A method comprising:

determining a cryptographic key in an integrated circuit based on a first digital value generated in the integrated circuit such that the first digital values substantially depends on circuit parameters that vary among like integrated circuits; and

performing a cryptographic function in the integrated circuit using the determined cryptographic key.

11. The method of claim 10 wherein determining the cryptographic key is further based on a second digital value.

12. The method of claim 11 further comprising determining the second digital value prior to determining the cryptographic key based on the first digital value, wherein the second digital value is based on the cryptographic key.

13. The method of claim 11 further comprising storing the second digital value in the integrated circuit.

14. The method of claim 10 wherein the method does not require non-volatile storage of the cryptographic key in the integrated circuit.

15. An integrated circuit comprising:

a key generator, including a component that generates a digital value such that the digital values substantially depends on circuit parameters that vary among like integrated circuits, and a component that determines a cryptographic key using the digital value; and

a cryptographic component coupled to the key generator to accept the determined cryptographic key.

16. The integrated circuit of claim 15 wherein the cryptographic component includes a decrypter.

17. The integrated circuit of claim 15 wherein the key generator includes a storage for a second digital value for combining with the generated digital value for determining the cryptographic key.