Network operator controlled locking and unlocking mechanism for mobile telephones

• US 6,321,079 B1
• Filed: 03/16/1999
• Issued: 11/20/2001
• Est. Priority Date: 03/18/1998
• Status: Expired due to Term

• Current Assignee: Lenovo Innovations Ltd Hong Kong (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Cooper, David Edward
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): Gary, Erika A.
• Application Number:
  US09/270,066
• Time in Patent Office: 980 Days
• Field of Search: 455/411, 455/410, 455/418, 455/558, 340/5.2, 340/5.8, 380/247, 380/249
• US Class Current: 455/411
• CPC Class Codes: H04W 12/108 Source integrity
• CPC Class Codes: H04W 12/48 using secure binding, e.g. securely binding identity modules to devices, services or applications
• CPC Class Codes: H04W 8/183 Processing at user equipment or user record carrier

Abstract

Network operator controlled locking and unlocking mechanism for mobile telephones is disclosed. A method and means for enabling the locking of a mobile telephone to a specified network by the network operator. Locking may be implemented at the point of sale of the mobile telephone. A secret number is embedded in the mobile telephone through the SIM (subscriber identity module) interface in the locking process and the secret number is used subsequently in combination with a random number to allow network unlock. The secret numbers may be indexed and administered in relation to the SIM rather than the mobile telephone.

Claims

1. A method for network operator control of locking and unlocking of a mobile telephone to selected networks, said method comprising the steps of:

causing said mobile telephone to store a secret number therein by an outer-module at the time of network locking;

instructing said mobile telephone to generate a random number by said outer-module at the time of network unlocking;

generating a random number, transmitting said random number to said outer-module, and generating a first value using said secret number and said random number by said mobile telephone;

generating a second value using said secret number and said random number transmitted from said mobile telephone by said outer-module;

transmitting said second value back to the mobile telephone by said outer-module; and

unlocking the network lock by said mobile telephone when said second value returned from said outer-module matches said first value.

2. A method for network operator control according to claim 1 wherein said outer-module is the SIM (subscriber identity module).

3. A method for network operator control according to claim 2 wherein the function which generates said first value and said second value using said secret number and said random number is based on random challenge authentication algorithms.

4. A method for network operator control according to claim 3 wherein said random challenge authentication algorithms are constructed in accordance with the GSM A3 of TS GSM 03.20, ‘

Security Related Network Functions’

published by European Telecommunications Standards Institute.

5. A method for network operator control according to claim 1 wherein said secret number is transmitted to said outer-module over the air interface.

6. A method for network operator control according to claim 5 wherein said outer-module is the SIM (subscriber identity module).

7. A method for network operator control according to claim 1 wherein the function which generates said first value and said second value using said secret number and said random number is based on random challenge authentication algorithms.

8. A method for network operator control according to claim 7 wherein said random challenge authentication algorithms are constructed in accordance with the GSM A3 of TS GSM.03.20, ‘

Security Related Network Functions’

published by European Telecommunications Standards Institute.

9. A mobile telephone comprising:

a non volatile memory for storing a secret number transmitted from an outer-module and network lock enabled flag indicating the current condition of a network lock; and

a central processing unit for causing said non volatile memory to store said secret number transmitted from said outer-module at the time of network locking, generating a random number in accordance with instructions transmitted from said outer-module at the time of network locking, transmitting said random number to said outer-module, generating a first value using said secret number stored in said non volatile memory and said random number, and unlocking the network lock when a second value returned from said outer-module matches said first value.

10. A mobile telephone according to claim 9 wherein said outer-module is the SIM (subscriber identity module).

11. A mobile telephone according to claim 10 wherein the function which generates said first value and said second value using said secret number and said random number is based on random challenge authentication algorithms.

12. A mobile telephone according to claim 11 wherein said random challenge authentication algorithms are constructed in accordance with the GSM A3 of TS GSM 03.20, ‘

Security Related Network Functions’

published by European Telecommunications Standards Institute.

13. A mobile telephone according to claim 9 wherein said secret number is transmitted to said outer-module over the air interface.

14. A mobile telephone according to claim 13 wherein said outer-module is the SIM (subscriber identity module).

15. A mobile telephone according to claim 9 wherein the function which generates said first value and said second value using said secret number and said random number is based on random challenge authentication algorithms.

16. A mobile telephone according to claim 15 wherein said random challenge authentication algorithms are constructed in accordance with the GSM A3 of TS GSM 03.20, ‘

Security Related Network Functions’

published by European Telecommunications Standards Institute.

17. A method for locking and unlocking of a mobile terminal to particular networks, comprising:

(a) storing a secret number in said mobile terminal;

(b) generating a random number by said mobile terminal;

(c) supplying said random number from said mobile terminal to a module device;

(d) generating a first value via said mobile terminal, wherein said first value is generated based on said secret number and said random number;

(e) generating a second value via said module device, wherein said second value is generated using said random number supplied from said mobile terminal and said secret number; and

(f) unlocking a network lock of said mobile terminal when said second value corresponds to said first value.

18. The method as claimed in claim 17, wherein said mobile terminal comprises a mobile telephone.

19. The method as claimed in claim 17, wherein said module device comprises a subscriber identity module.

20. The method as claimed in claim 17, wherein said operation (a) comprises:

(a1) outputting said secret number from said module device to said mobile terminal; and

(a2) storing said secret number in said mobile terminal.

21. The method as claimed in claim 20, wherein said operation (b) comprises:

(b1) outputting an instruction from said module device to said mobile terminal; and

(b2) generating said random number by said mobile terminal in response to said instruction, and wherein said operation (f) comprises;

(f1) outputting said second value from said module device to said mobile terminal;

(f2) determining, via said mobile terminal, a relationship between said first value and said second value; and

(f3) unlocking said network lock of said mobile terminal when said second value corresponds to said first value.

22. The method as claimed in claim 17, wherein said operation (b) comprises:

(b1) outputting an instruction from said module device to said mobile terminal; and

(b2) generating said random number by said mobile terminal in response to said instruction.

23. The method as claimed in claim 17, wherein said operation (f) comprises:

(f1) outputting said second value from said module device to said mobile terminal;

(f2) determining, via said mobile terminal, a relationship between said first value and said second value; and

(f3) unlocking said network lock of said mobile terminal when said second value corresponds to said first value.

24. The method as claimed in claim 23, wherein said operation (f3) comprises:

(f3a) unlocking said network lock of said mobile terminal when said second value equals said first value.

25. A mobile terminal system, comprising:

a module device; and

a mobile terminal having a memory and a processor,

wherein said memory stores a secret number,

wherein said processor generates a random number and supplies said random number to said module device,

wherein said processor generates a first value based on said secret number and said random number,

wherein said module device generates a second value using said random number supplied from said mobile terminal and said secret number, and

wherein said processor unlocks a network lock of said mobile terminal when said second value corresponds to said first value.

26. The system as claimed in claim 25, wherein said memory is a non-volatile memory.

27. The system as claimed in claim 25, wherein said mobile terminal comprises a mobile telephone.

28. The system as claimed in claim 25, wherein said module device comprises a subscriber identity module.

29. The system as claimed in claim 25, wherein said module device outputs said secret number to said mobile terminal before said secret number is stored in said memory.

30. The system as claimed in claim 25, wherein said module device outputs an instruction to said processor, and

wherein said processor generates said random number in response to said instruction.

31. The system as claimed in claim 25, wherein said module device outputs said second value to said processor,

wherein said processor determines a relationship between said first value and said second value, and

wherein said processor unlocks said network lock of said mobile terminal when said second value corresponds to said first value.

32. The system as claimed in claim 31, wherein said processor unlocks said network lock of said mobile terminal when said second value equals said first value.