Method for protecting electronic device, and electronic device

• US 20030021413A1
• Filed: 06/28/2002
• Published: 01/30/2003
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Asokan, Nadarajah, Kiiveri, Antti, Niemi, Valtteri
• Granted Patent: US 7,630,495 B2
• Time in Patent Office: Days
• US Class Current: 380/247
• CPC Class Codes: H04W 12/08 Access security
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

Identity data of an operational unit and a verification key of the cryptographic method employed by the service provider are protected with a key of the cryptographic method employed by the manufacturer of the operational unit. The verification key of the cryptographic method employed by the manufacturer of the operational unit is stored in the operational unit of the electronic device. The identity data of the operational unit and the identity data of the service provider are protected with a key of the cryptographic method employed by the service provider. The identity data of the operational unit and the verification key of the service provider are verified with the verification key of the manufacturer of the operational unit. The identity data of the operational unit and the identity data of the service provider are verified with the verified verification key of the service provider. The identity data stored in the user-specific module are compared with the verified identity data. The device starts if the identity data verified by the cryptographic method correspond with the identity data stored in the user-specific module.

Claims

1. A method for protecting an electronic device which comprises an operational unit and a user-specific module and which is intended to communicate with a radio network, the method comprising

protecting both identity data of the operational unit and a verification key of the cryptographic method employed by a service provider with a key of the cryptographic method employed by the manufacturer of the operational unit;

and

storing a verification key of the cryptographic method employed by the operational unit for verifying the identity data of the operational unit and the key of the cryptographic method employed by the service provider.

2. A method as claimed in claim 1, performing the protection of both the identity data of the operational unit and the key of the cryptographic method employed by the service provider with a secret key of the public key cryptographic method employed by the manufacturer of the operational unit;

and

storing in the operational unit a public key of the public key cryptographic method employed by the manufacturer of the operational unit to serve as a verification key.

3. A method as claimed in claim 1, performing the protection of both the identity data of the operational unit and the key of the cryptographic method employed by the service provider by MAC cryptographic method employed by the manufacturer of the operational unit;

and

storing a key of the MAC cryptographic method in the operational unit of the electronic device to serve as a verification key.

4. A method as claimed in claim 1, protecting both the identity data of the operational unit and the identity data of the service provider with a key of the cryptographic method employed by the service provider.

5. A method as claimed in claim 4, performing the protection of the identity data of the operational unit and the identity data of the user with a secret key of the public key cryptographic method employed by the service provider.

6. A method as claimed in claim 4, performing the protection of both the identity data of the operational unit and the identity data of the user by the MAC cryptographic method employed by the service provider;

and

storing unprotected data in the operational unit of the electronic device.

21. A method as claimed in claim 1 or 7, altering the identity data of the service provider such that the service provider'"'"'s new identity data is entered in the electronic device, which information is protected with a key of the cryptographic method employed by the service provider.

22. A method as claimed in claim 21, setting, if the service provider desires to cancel the protection between the operational unit and the user-specific module, a predetermined code, by which the service provider leaves the relation between the operational unit and the user-specific module unprotected, as the verification key of the cryptographic method employed by the service provider.

23. A method as claimed in claim 21, entering, if the verification key of the service provider is desired to be changed, the service provider'"'"'s new verification key in the electronic device, which new verification key is protected with a key of the cryptographic method employed by the manufacturer of the electronic device.

24. A method as claimed in claim 1, 4 or 7, wherein the identity data of the operational unit comprises more than one identities.

25. A method as claimed in claim 1 or 7, wherein the electronic device is a terminal equipment of a radio system, the service provider is an operator, the identity data of the service provider is one or more IMSI codes, or IMSI code'"'"'s partial codes, and the identity data of the operational unit is one or more IMEI codes, or IMEI code'"'"'s partial codes.

7. A method for protecting an electronic device which comprises an operational unit and a user-specific module and which is intended to communicate with a radio network, wherein both the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider being protected with a key of the cryptographic method employed by the manufacturer of the operational unit, and the verification key of the cryptographic method employed by the manufacturer of the operational unit being stored in the operational unit of the electronic device;

and both the identity data of the operational unit and the identity data of the service provider being protected with a key of the cryptographic method employed by the service provider;

the method comprising

verifying the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider with a verification key of the cryptographic method employed by the manufacturer of the operational unit, and if the verification fails, the electronic device is at least blocked from connecting to the radio network;

verifying both the identity data of the operational unit and the identity data of the service provider with the verification key of the cryptographic method employed by the service provider, which verification key is verified with the verification key of the cryptographic method employed by the manufacturer of the operational unit, and if the verification fails, the electronic device is at least blocked from connecting to the radio network;

comparing the identity data of the operational unit and the identity data of the service provider stored in the user-specific module with the verified identity data of the operational unit and the verified identity data of the service provider; and

if the identity data of the operational unit and the identity data of the service provider verified by the cryptographic method correspond with the identity data of the operational unit and the identity data of the service provider read from the user-specific module, the electronic device is started, otherwise the electronic is at least blocked from connecting to the radio network.

8. A method as claimed in claim 7, if the verification key of the cryptographic method employed by the service provider is a predetermined code, by which the service provider leaves the relation between the operational unit and the user-specific module unprotected, the rest of the steps are omitted and the electronic device is started, otherwise the process continues step by step.

9. A method as claimed in claim 7, wherein the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider are protected with a secret key of the public key cryptographic method employed by the manufacturer of the operational unit, the public key of the public key cryptographic method employed by the manufacturer of the operational unit being stored in the operational unit of the electronic device to serve as a verification key;

the method comprising

verifying the identity data of the operational unit and the key of the cryptographic method employed by the service provider with the public key of the public key cryptographic method employed by the manufacturer of the operational unit stored as the verification key.

10. A method as claimed in claim 9, wherein both the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider are protected with a signature which is generated by the public key cryptographic method using the secret key of the manufacturer of the operational unit, wherein

verifying the identity data of the operational unit and the key of the cryptographic method employed by the service provider by checking the signature using the public key of the public key cryptographic method as the verification key.

11. A method as claimed in claim 9, wherein both the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider are encrypted with the secret key of the public key cryptographic method employed by the manufacturer of the operational unit, the method comprising

verifying the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider by decrypting the identity data and the verification key of the cryptographic method employed by the service provider with the public key of the public key cryptographic method serving as the verification key.

12. A method as claimed in claim 7, wherein both the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider are protected by MAC cryptographic method employed by the manufacturer of the operational unit, and the key of the MAC cryptographic method employed by the manufacturer of the operational unit, the unprotected identity data of the operational unit and the unprotected verification key of the cryptographic method employed by the service provider are stored in the operational unit of the electronic device;

the method comprising

verifying the identity data of the operational unit and the key of the cryptographic method employed by the service provider with the MAC key of the operational unit manufacturer.

13. A method as claimed in claim 12, wherein performing a reference MAC encryption on the MAC key of the operational unit manufacturer and the unprotected identity data of the operational unit and the unprotected key of the cryptographic method employed by the service provider;

performing verification such that the result of the reference MAC encryption is compared with the original MAC encryption result, and if the encryption results are identical, the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider are considered as verified.

14. A method as claimed in claim 7, wherein both the identity data of the operational unit and the identity data of the service provider are protected with the secret key of the public key cryptographic method employed by the service provider;

the method comprising

verifying both the identity data of the operational unit and the identity data of the service provider with the public key of the public key cryptographic method employed by the service provider serving as the verification key.

15. A method as claimed in claim 14, wherein both the identity data of the operational unit and the identity data of the service provider are protected with a signature which is generated by a public key cryptographic method using a secret key of the public key cryptographic method employed by the service provider, the method comprising

verifying the identity data of the operational unit and the identity data of the service provider by checking the signature using the public key of the public key cryptographic method.

16. A method as claimed in claim 14, wherein both the identity data of the operational unit and the identity data of the service provider are encrypted with the secret key of the public key cryptographic method employed by the service provider, the method comprising

verifying the identity data of the operational unit and the identity data of the service provider by decrypting the identity data and the user identity data with the public key of the public cryptographic method.

17. A method as claimed in claim 7, wherein the identity data of the operational unit and the identity data of the service provider being protected by the MAC cryptographic method employed by the service provider, the method comprising

verifying both the identity data of the operational unit and the identity data of the service provider with the MAC key of the service provider serving as the verification key.

18. A method as claimed in claim 17, performing a reference MAC encryption on the MAC key of the service provider and both the unprotected identity data of the operational unit and the unprotected identity data of the service provider;

performing the protection such that the result of the reference MAC encryption is compared with the original MAC encryption result, and if the results are identical, the identity data of the operational unit and the identity data of the service provider are considered as verified.

19. A method as claimed in claim 17, generating a key K_od of the MAC cryptographic method employed by the service provider as a pseudorandom function from the key K and the service provider'"'"'s identity data OP_id, where the key K is the key of the manufacturer of the operational unit.

20. A method as claimed in claim 7, comparing the verified identity data of the operational unit with the identity data of the operational unit stored in the user-specific module after the verification of the identity data of the operational unit and the key of the cryptographic method employed by the service provider;

and

if the identity data of the operational unit to be compared differ from one another, the electronic device is at least blocked from connecting to the radio network.

26. An electronic device which comprises an operational unit and a user-specific module and which is arranged to communicate with a radio network, wherein both the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider are protected with a key of the cryptographic method employed by the manufacturer of the operational unit, and the verification key of the cryptographic method employed by the manufacturer of the operational unit is stored in the operational unit of the electronic device;

and both the identity data of the operational unit and the identity data of the service provider are protected with the key of the cryptographic method employed by the service provider;

the electronic device is arranged to verify the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider with the verification key of the cryptographic method employed by the manufacturer of the operational unit, and if the verification fails, the electronic device is arranged to restrict its operation at least by not connecting to the radio network;

the electronic device is arranged to verify both the identity data of the operational unit and the identity data of the service provider with said verification key of the cryptographic method employed by the service provider, which verification key is verified with the key of the cryptographic method employed by the manufacturer of the operational unit, and if the verification fails, the electronic device is arranged to restrict its operation at least by not connecting to the radio network;

the electronic device is arranged to compare the identity data of the operational unit and the identity data of the service provider stored in the user-specific module with the verified identity data of the operational unit and the verified identity data of the service provider; and

the electronic device is arranged to start if both the identity data of the operational unit and the identity data of the service provider, verified by the cryptographic method, correspond with the identity data of the operational unit and the identity data of the service provider, stored in the user-specific module, otherwise the electronic device is arranged to restrict its operation at least by not connecting to the radio network.

27. A device as claimed in claim 26, wherein the electronic device is arranged to start if the verification key of the cryptographic method employed by the service provider is a predetermined code, by which the service provider leaves the relation between the operational unit and the user-specific module unprotected.

28. A device as claimed in claim 26, wherein both the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider being protected with the secret key of the public key cryptographic method of the manufacturer of the operational unit and the public key of the public key cryptographic method employed by the manufacturer of the operational unit being stored as a verification key in the operational unit of the electronic device

the electronic device is arranged to verify the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider with the public key of the public key cryptographic method employed by the manufacturer of the operational unit .

29. A device as claimed in claim 28, wherein both the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider are protected with a signature which is generated by the public key cryptographic method using the secret key of the manufacturer of the operational unit, and

the electronic device is arranged to verify the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider by checking the signature using the public key of the public key cryptographic method.

30. A device as claimed in claim 28, wherein both the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider are encrypted with the secret key of the public key cryptographic method employed by the manufacturer of the operational unit, and

the electronic device is arranged to verify the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider by decrypting the identity data and the verification key of the cryptographic method employed by the service provider with the public key of the public key cryptographic method.

31. A device as claimed in claim 26, wherein the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider are protected by the MAC cryptographic method employed by the manufacturer of the operational unit, and the MAC key of the manufacturer of the operational unit, unprotected identity data of the operational unit and an unprotected verification key of the cryptographic method employed by the service provider are stored in the operational unit of the electronic device;

the electronic device is arranged to verify the identity data of the operational unit and the verification key of the cryptographic method employed by the MAC key of the manufacturer of the operational unit.

32. A device as claimed in claim 31, wherein a reference MAC encryption is performed on the MAC key used by the manufacturer of the operational unit and the unprotected identity data of the operational unit and the unprotected key of the cryptographic method employed by the service provider;

the electronic device is arranged to perform the verification such that the result of the reference MAC encryption is compared with the result of the original MAC encryption and if the results are identical, the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider are verified.

33. A device as claimed in claim 26, wherein both the identity data of the operational unit and the identity data of the service provider are protected with a secret key of the public key cryptographic method of the service provider;

the electronic device is arranged to verify both the identity data of the operational unit and the identity data of the service provider with the public key of the public key cryptographic method employed by the service provider serving as the verification key.

34. A device as claimed in claim 33, wherein both the identity data of the operational unit and the identity data of the service provider are protected with a signature which is generated by the public key cryptographic method using the secret key of the service provider, and

the electronic device is arranged to verify the identity of the operational unit and the identity data of the service provider by checking the signature using the public key of the public key cryptographic method.

35. A device as claimed in claim 33, wherein both the identity data of the operational unit and the identity data of the service provider are encrypted with the secret key of the public key cryptographic method employed by the service provider, and

the electronic device is arranged to verify the identity data of the operational unit and the identity data of the service provider by decrypting the identity data and the user identity data by means of the public key of the public key cryptographic method serving as the verification key.

36. A device as claimed in claim 26, wherein the identity data of the operational unit and the identity data of the service provider being protected by the MAC cryptographic method employed by the service provider,

the electronic device is arranged to verify both the identity data of the operational unit and the identity data of the service provider with the MAC key of the service provider serving as the verification key.

37. A device as claimed in claim 36, wherein a reference MAC encryption is performed on the MAC key used by the service provider and the unprotected identity data of the operational unit and the unprotected identity data of the service provider;

the electronic device is arranged to perform the verification such that the result of the reference MAC encryption is compared with the original MAC encryption result and if the encryption results are identical, the identity data of the operational unit and the identity data of the service provider are verified.

38. A device as claimed in claim 36, wherein the electronic device is arranged to generate the key K_od of the MAC cryptographic method employed by the service provider as a pseudo-random function from the key K and the service provider'"'"'s identity data OP_id, where K is the common key of the manufacturer and the operational unit of the electronic device.

39. A device as claimed in claim 26, wherein after verifying the identity data of the operational unit and the verification key of the cryptographic method employed by the service provider

the electronic device is arranged to compare the verified identity data of the operational unit with the identity data of the operational unit stored in the user-specific module;

the electronic device is arranged to restrict its operation at least by not connecting to the radio network if the compared identity data of the operational unit differ from one another.

40. A device as claimed in claim 26, wherein for altering both the identity data of the operational unit and the identity data of the service provider the electronic device is arranged to receive both the operational unit'"'"'s new identity data and the service provider'"'"'s new identity data, which are protected with a key of the cryptographic method employed by the service provider.

41. A device as claimed in claim 40, wherein if the service provider desires to unlock the locking between the operational unit and the user-specific module

the electronic device is arranged to receive for use as a verification key of the cryptographic method employed by the service provider, a predetermined code by which the service provider leaves the relation between the operational unit and the user-specific module unprotected.

42. A device as claimed in claim 40, wherein if the verification key of the service provider is desired to be changed, the electronic device is arranged to receive the service provider'"'"'s new verification key, which is protected with the key of the cryptographic method employed by the manufacturer of the electronic device.

43. A device as claimed in claim 26, wherein the identity data of the operational unit comprises more than one identity.

44. A device as claimed in claim 26, wherein the electronic device is a radio system terminal equipment, the service provider is an operator, the identity data of the service provider is one or more IMSI codes or IMSI code'"'"'s partial codes and the identity data of the operational unit is one or more IMEI codes or IMEI code'"'"'s partial codes.