CRYPTOGRAPHIC COMMUNICATION SYSTEM AND CRYPTOGRAPHIC COMMUNICATION METHOD

• US 20120321077A1
• Filed: 06/13/2012
• Published: 12/20/2012
• Est. Priority Date: 06/20/2011
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: SHIOTA, Shigemasa, Hirokawa, Masayuki, Yamazaki, Akira, Oshida, Daisuke, Furuta, Shigeru
• Granted Patent: US 9,363,082 B2
• Time in Patent Office: Days
• US Class Current: 380/44
• CPC Class Codes: H04L 2209/04 Masking or blinding
• CPC Class Codes: H04L 2209/24 Key scheduling, i.e. generating round keys or sub-keys for block encryption
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 2209/84 Vehicles
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0861 Generation of secret information including derivation or calculation of cryptographic keys or passwords
• CPC Class Codes: H04L 9/0866 involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics
• CPC Class Codes: H04L 9/0869 involving random numbers or seeds
• CPC Class Codes: H04L 9/14 using a plurality of keys or algorithms
• CPC Class Codes: H04L 9/30 Public key, i.e. encryption algorithm being computationally infeasible to invert or user's encryption keys not requiring secrecy
• CPC Class Codes: H04L 9/304 based on error correction codes, e.g. McEliece
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/3278 using physically unclonable functions [PUF]

Abstract

Provided is a cryptographic communication system including a first semiconductor device and a second semiconductor device. The first semiconductor device includes a common key generation unit that generates a common key CK(a) by using a unique code UC(a) and correction data CD(a), and an encryption unit that encrypts the common key CK(a) generated in the common key generation unit by using a public key PK(b) of the second semiconductor device. The second semiconductor device includes a secret key generation unit that generates a secret key SK(b) by using a unique code UC(b) and correction data CD(b), and a decryption unit that decrypts the common key CK(a) encrypted in the encryption unit by using the secret key SK(b).

Claims

1. A cryptographic communication system including a first semiconductor device and a second semiconductor device,

the first semiconductor device comprising:

a common key generation unit that generates a common key by using a first unique code having a value unique to the first semiconductor device and containing a random error and first correction data for correcting the first unique code; and

an encryption unit that encrypts the common key generated in the common key generation unit by using a public key of the second semiconductor device, and

the second semiconductor device comprising;

a secret key generation unit that generates a secret key of the second semiconductor device by using a second unique code having a value unique to the second semiconductor device and containing a random error and second correction data for correcting the second unique code; and

a decryption unit that decrypts the common key encrypted in the encryption unit by using the secret key.

2. The cryptographic communication system according to claim 1, wherein the first semiconductor device and the second semiconductor device communicate using the common key.

3. The cryptographic communication system according to claim 1, wherein the first correction data includes mask data for masking a bit with a high error rate among bits of the first unique code, and an error correction code for correcting a bit with a low error rate among bits of the first unique code.

4. The cryptographic communication system according to claim 3, wherein the first correction data further includes an operation parameter for performing a specified operation on the first unique code error-corrected using the mask data and the error correction code.

5. The cryptographic communication system according to claim 4, wherein the common key generation unit masks the first unique code using the mask data, corrects an error of the masked first unique code using the error correction code, and performs an operation on the first unique code error-corrected using the mask data and the error correction code by using the operation parameter.

6. The cryptographic communication system according to claim 1, wherein the first and second semiconductor devices are configured using secure microcomputers.

7. The cryptographic communication system according to claim 1, wherein the first and second semiconductor devices are configured using general-purpose microcomputers.

8. The cryptographic communication system according to claim 1, wherein the first and second semiconductor devices are vehicle-mounted microcomputers.

9. The cryptographic communication system according to claim 8, wherein one of the first and second semiconductor devices is a fault diagnostic unit.

10. The cryptographic communication system according to claim 8, wherein one of the first and second semiconductor devices is a car navigation system.

11. A cryptographic communication system including a first semiconductor device and a second semiconductor device,

the first semiconductor device comprising:

a secret key generation unit that generates a secret key of the first semiconductor device by using a first unique code having a value unique to the first semiconductor device and containing a random error and first correction data for correcting the first unique code; and

a signature data generation unit that generates signature data by using the secret key and a plain text, and

the second semiconductor device comprising;

a verification unit that generates verification data by using the signature data and a public key of the first semiconductor device and compares the verification data with the plain text.

12. The cryptographic communication system according to claim 11, wherein the second semiconductor device comprises:

a public key generation unit that generates a public key of the first semiconductor device by using a second unique code having a value unique to the second semiconductor device and containing a random error and second correction data for correcting the second unique code.

13. The cryptographic communication system according to claim 11, wherein the first correction data includes mask data for masking a bit with a high error rate among bits of the first unique code, and an error correction code for correcting a bit with a low error rate among bits of the first unique code.

14. The cryptographic communication system according to claim 13, wherein the first correction data further includes an operation parameter for performing a specified operation on the first unique code error-corrected using the mask data and the error correction code.

15. The cryptographic communication system according to claim 14, wherein the secret key generation unit masks the first unique code using the mask data, corrects an error of the masked first unique code using the error correction code, and performs an operation on the first unique code error-corrected using the mask data and the error correction code by using the operation parameter.

16. The cryptographic communication system according to claim 11, wherein the first and second semiconductor devices are configured using secure microcomputers.

17. The cryptographic communication system according to claim 11, wherein the first and second semiconductor devices are configured using general-purpose microcomputers.

18. The cryptographic communication system according to claim 11, wherein the first and second semiconductor devices are vehicle-mounted microcomputers.

19. The cryptographic communication system according to claim 18, wherein one of the first and second semiconductor devices is a fault diagnostic unit.

20. The cryptographic communication system according to claim 18, wherein one of the first and second semiconductor devices is a car navigation system.

21. A cryptographic communication system including first to third semiconductor devices, wherein

the third semiconductor device is configured to supply first correction data for correcting a first unique code to the first semiconductor device and supply second correction data for correcting a second unique code to the second semiconductor device,

the first semiconductor device includes a first common key generation unit that generates a common key by using a first unique code having a value unique to the first semiconductor device and containing a random error and the first correction data supplied from the third semiconductor device, and

the second semiconductor device includes a second common key generation unit that generates a common key by using a second unique code having a value unique to the second semiconductor device and containing a random error and the second correction data supplied from the third semiconductor device.

22. The cryptographic communication system according to claim 21, wherein the third semiconductor device includes a database that stores correction data associated with respective semiconductor devices and commons keys generated in the respective semiconductor device.

23. The cryptographic communication system according to claim 21, wherein the third semiconductor device includes a correction data generation unit that generates the first correction data by using a common key and a first unique code having a value unique to the first semiconductor device and containing a random error, and generates the second correction data by using the common key and a second unique code having a value unique to the second semiconductor device and containing a random error.

24. The cryptographic communication system according to claim 21, wherein

the third semiconductor device includes a correction data generation unit that generates the first correction data by using a first common key and a first unique code having a value unique to the first semiconductor device and containing a random error, and generates the second correction data by using a second common key and a second unique code having a value unique to the second semiconductor device and containing a random error,

the first common key generation unit included in the first semiconductor device generates the first common key,

the second common key generation unit included in the second semiconductor device generates the second common key,

the first semiconductor device and the third semiconductor device communicate using the first common key, and

the second semiconductor device and the third semiconductor device communicate using the second common key.

25. The cryptographic communication system according to claim 21, wherein the first correction data is supplied to the first semiconductor device in an encrypted state, and the second correction data is supplied to the second semiconductor device in an encrypted state.

26. The cryptographic communication system according to claim 23, wherein the correction data generation unit acquires the first unique code a plurality of times, generates mask data for masking a bit with a high error rate among bits of the acquired first unique code, and generates an error correction code for correcting a bit with a low error rate among bits of the acquired first unique code.

27. The cryptographic communication system according to claim 26, wherein the correction data generation unit further generates an operation parameter by using the common key and the first unique code error-corrected using the mask data and the error correction code.

28. The cryptographic communication system according to claim 21, wherein

the third semiconductor device is configured using a secure microcomputer, and

the first and second semiconductor devices are configured using general-purpose microcomputers.

29. The cryptographic communication system according to claim 21, wherein the first to third semiconductor devices are vehicle-mounted microcomputers.

30. The cryptographic communication system according to claim 24, wherein

the first and second semiconductor devices are vehicle-mounted microcomputers,

the third semiconductor device is a gateway unit, and

the first and second semiconductor devices communicate through the gateway unit.

31. The cryptographic communication system according to claim 29, wherein one of the first and second semiconductor devices is a fault diagnostic unit.

32. The cryptographic communication system according to claim 29, wherein one of the first and second semiconductor devices is a car navigation system.

33. A cryptographic communication method using a first semiconductor device and a second semiconductor device, comprising:

in the first semiconductor device,

generating a common key by using a first unique code having a value unique to the first semiconductor device and containing a random error and first correction data for correcting the first unique code;

encrypting the generated common key by using a public key of the second semiconductor device; and

in the second semiconductor device,

generating a secret key of the second semiconductor device by using a second unique code having a value unique to the second semiconductor device and containing a random error and second correction data for correcting the second unique code; and

decrypting the encrypted common key by using the secret key.

34. A cryptographic communication method using a first semiconductor device and a second semiconductor device, comprising:

in the first semiconductor device,

generating a secret key of the first semiconductor device by using a first unique code having a value unique to the first semiconductor device and containing a random error and first correction data for correcting the first unique code;

generating signature data by using the secret key and a plain text; and

in the second semiconductor device,

generating verification data by using the signature data and a public key of the first semiconductor device, and comparing the verification data with the plain text.

35. A cryptographic communication method using first to third semiconductor devices, comprising:

transmitting first correction data for correcting a first unique code from the third semiconductor device to the first semiconductor device;

generating a common key in the first semiconductor device by using a first unique code having a value unique to the first semiconductor device and containing a random error and the first correction data supplied from the third semiconductor device;

transmitting second correction data for correcting a second unique code from the third semiconductor device to the second semiconductor device; and

generating a common key in the second semiconductor device by using a second unique code having a value unique to the second semiconductor device and containing a random error and the second correction data supplied from the third semiconductor device.

36. A cryptographic communication system including a first semiconductor device and a second semiconductor device,

the first semiconductor device comprising:

a first common key generation unit that generates a first common key by using a first unique code having a value unique to the first semiconductor device and containing a random error and first correction data for correcting the first unique code; and

a correction data generation unit that generates second correction data for correcting a second unique code by using the first common key generated in the first common key generation unit and a second unique code having a value unique to the second semiconductor device and containing a random error, and

the second semiconductor device comprising;

a second common key generation unit that generates the first common key by using the second unique code and the second correction data.

37. The cryptographic communication system according to claim 36, wherein

the second semiconductor device further includes an encryption unit that encrypts the second unique code by using a public key of the first semiconductor device, and

the first semiconductor device further includes a decryption unit that decrypts the second unique code encrypted in the encryption unit by using a secret key of the first semiconductor device.

38. The cryptographic communication system according to claim 36, wherein

the cryptographic communication system further includes a server including a database that stores public keys of respective semiconductor devices in association with the respective semiconductor devices,

the second semiconductor device generates signature data by using a secret key of the second semiconductor device and a plain text, and

the first semiconductor device further includes a verification unit that generates verification data by using the signature data of the second semiconductor device and a public key of the second semiconductor device transmitted from the server, and compares the verification data with the plain text.

39. The cryptographic communication system according to claim 37, wherein

the encryption unit included in the second semiconductor device further encrypts a correction data generation program for generating second correction data using the first common key generated in the first common key generation unit and the second unique code by using the public key of the first semiconductor device,

the decryption unit included in the first semiconductor device further decrypts the encrypted correction data generation program by using the secret key of the first semiconductor device, and

the first semiconductor device executes the decrypted correction data generation program and generates the second correction data by using the first common key and the second unique code.

40. The cryptographic communication system according to claim 36, wherein the first semiconductor device and the second semiconductor device communicate using the first common key.

41. The cryptographic communication system according to claim 40, wherein

the first common key generation unit further generates a second common key by using the first unique code unique to the first semiconductor device and third correction data, and

the first semiconductor device communicates with the third semiconductor device using the second common key, and

the second semiconductor device communicates with the third semiconductor device through the first semiconductor device.

42. The cryptographic communication system according to claim 36, wherein the first correction data includes first mask data for masking a bit with a high error rate among bits of the first unique code, and a first error correction code for correcting a bit with a low error rate among bits of the first unique code.

43. The cryptographic communication system according to claim 42, wherein the first correction data further includes a first operation parameter for performing a specified operation on the first unique code error-corrected using the first mask data and the first error correction code.

44. The cryptographic communication system according to claim 43, wherein the first common key generation unit masks the first unique code using the first mask data, corrects an error of the masked first unique code using the first error correction code, and performs an operation on the first unique code error-corrected using the first mask data and the first error correction code by using the first operation parameter.

45. The cryptographic communication system according to claim 36, wherein the second correction data is transmitted from the first semiconductor device to the second semiconductor device in an encrypted state.

46. The cryptographic communication system according to claim 36, wherein the correction data generation unit acquires the second unique code a plurality of times, generates second mask data for masking a bit with a high error rate among bits of the acquired second unique code, generates a second error correction code for correcting a bit with a low error rate among bits of the acquired second unique code, and generates a second operation parameter by using the first common key and the second unique code error-corrected using the second mask data and the second error correction code.

47. The cryptographic communication system according to claim 46, wherein a process of generating the correction data is executed in a distributed manner among a plurality of semiconductor devices.

48. The cryptographic communication system according to claim 36, wherein the first semiconductor device is configured using a secure microcomputer.

49. The cryptographic communication system according to claim 36, wherein the first and second semiconductor devices are configured using general-purpose microcomputers.

50. The cryptographic communication system according to claim 36, wherein the first and second semiconductor devices are vehicle-mounted microcomputers.

51. The cryptographic communication system according to claim 36, wherein

the first semiconductor device is a vehicle-mounted microcomputer forming an in-vehicle network, and

the second semiconductor device is a car navigation system.

52. A cryptographic communication method using a first semiconductor device and a second semiconductor device, comprising:

in the first semiconductor device,

generating a first common key by using a first unique code having a value unique to the first semiconductor device and containing a random error and first correction data for correcting the first unique code;

generating second correction data for correcting a second unique code by using the generated first common key and a second unique code having a value unique to the second semiconductor device and containing a random error; and

in the second semiconductor device,

generating the first common key by using the second unique code and the second correction data.

53. The cryptographic communication method according to claim 52, comprising:

encrypting the second unique code by using a public key of the first semiconductor device in the second semiconductor device, and

decrypting the encrypted second unique code by using a secret key of the first semiconductor device in the first semiconductor device.

54. The cryptographic communication method according to claim 52, comprising:

generating signature data by using a secret key of the second semiconductor device and a plain text in the second semiconductor device; and

generating verification data by using a public key of the second semiconductor device transmitted from a server including a database that stores public keys of respective semiconductor devices in association with the respective semiconductor devices and the signature data of the second semiconductor device, and comparing the verification data with the plain text.

55. The cryptographic communication method according to claim 53, comprising:

in the second semiconductor device,

encrypting a correction data generation program for generating the second correction data using the first common key and the second unique code by using the public key of the first semiconductor device;

in the first semiconductor device,

decrypting the encrypted correction data generation program; and

executing the decrypted correction data generation program and generating the second correction data by using the first common key and the second unique code.

56. The cryptographic communication method according to claim 52, wherein the first semiconductor device and the second semiconductor device communicate using the first common key.

57. The cryptographic communication method according to claim 56, comprising:

generating a second common key by using the first unique code unique to the first semiconductor device and third correction data in the first common key generation unit, wherein

the first semiconductor device communicates with the third semiconductor device using the second common key, and

the second semiconductor device communicates with the third semiconductor device through the first semiconductor device.