Method for changing an operating mode of a mobile device

1. A method for changing an operating mode of a mobile device, the method comprising the steps of:

receiving a request from a user of the mobile device to change from a first operating mode to a second operating mode,

requesting a credential from the user in response to the received request,

receive the credential from the user,

validating the received credential,

setting the second operating mode and setting an indication of the mobile device indicating that the second operating mode has been set, and

after the second operating mode has been set, prohibiting a reset of the indication indicating that the second operating mode has been set and refusing access to a hardware unique key stored on the mobile device.

2. The method according to claim 1 , wherein the indication comprises a device identifier of the mobile device, and wherein the step of setting the indication comprises erasing the device identifier.

3. The method according to claim 1 , wherein the indication relates to a section of a memory unit of the mobile device, and wherein the step of setting the indication comprises storing the received credential in the section of the memory unit.

4. The method according to claim 1 , wherein the first operating mode comprises a user mode and the second operating mode comprises a developer mode,

wherein an operation software download function and a debug function for debugging software running on the mobile device are enabled in the developer mode and disabled in the user mode, and

wherein an access to user data stored in the mobile device is disabled in the developer mode and enabled in the user mode.

5. The method according to claim 1 , wherein setting the second operating mode comprises erasing at least part of user data stored in the mobile device.

6. The method according to claim 1 , wherein the second operating mode and the indication are not set, if a SIM lock indication of the mobile device is set, the SIM lock indication indicating that the mobile device is allowed to be operated only in connection with a specific subscriber identity module.

7. The method according to claim 1 , wherein the step of validating the received credential comprises:

encoding the received credential with a predetermined unidirectional encoding scheme, and

comparing the encoded received credential with an encoded reference credential stored in the mobile device.

8. The method according to claim 1 , wherein the credential is derived from a predetermined key information and an IMEI information of the mobile device, wherein the IMEI information comprises an international mobile equipment identity which is unique for the mobile device.

9. A mobile device, comprising:

an input device for receiving input information from a user of the mobile device,

an output device for outputting output information to the user, and

a processing unit adapted to

receive via the input device a request from the user to change from a first operating mode of the mobile device to a second operating mode of the mobile device,

request a credential from the user in response to the received request,

receive a credential from the user,

validate the received credential, and

if the received credential is valid, set the second operating mode, set an indication of the mobile device indicating that the second operating mode has been set, prohibit resetting the indication indicating that the second operating mode has been set, and refuse access to a hardware unique key stored on the mobile device.

10. The mobile device according to claim 9 , wherein the mobile device comprises at least one of the group comprising a mobile phone, a personal digital assistant, a digital camera, and a navigation system.

11. The mobile device of claim 9 , wherein the indication comprises a device identifier of the mobile device, and wherein the step of setting the indication comprises erasing the device identifier.

12. The mobile device of claim 9 , wherein the indication relates to a section of a memory unit of the mobile device, and wherein the step of setting the indication comprises storing the received credential in the section of the memory unit.

13. The mobile device of claim 9 , wherein the first operating mode comprises: a user mode and the second operating mode comprises a developer mode, wherein an operation software download function and a debug function for debugging software running on the mobile device are enabled in the developer mode and disabled in the user mode, and wherein an access to user data stored in the mobile device is disabled in the developer mode and enabled in the user mode.

14. The mobile device of claim 9 , wherein setting the second operating mode comprises erasing at least part of user data stored in the mobile device.

15. The mobile device of claim 9 , wherein the second operating mode and the indication are not set, if a SIM lock indication of the mobile device is set, the SIM lock indication indicating that the mobile device is allowed to be operated only in connection with a specific subscriber identity module.

16. The mobile device of claim 9 , wherein the step of validating the received credential comprises:

encoding the received credential with a predetermined unidirectional encoding scheme, and

comparing the encoded received credential with an encoded reference credential stored in the mobile device.

17. The mobile device of claim 9 , wherein the credential is derived from a predetermined key information and an IMEI information of the mobile device, wherein the IMEI information comprises an international mobile equipment identity which is unique for the mobile device.

18. A method for changing an operating mode of a mobile device, the method comprising:

receiving a request from a user of the mobile device to change from a first operating mode to a second operating mode,

requesting a credential from the user in response to the received request,

receive the credential from the user,

validating the received credential,

setting the second operating mode and setting an indication of the mobile device indicating that the second operating mode has been set, wherein the indication relates to a section of a memory unit of the mobile device which has limited access, and wherein the setting the indication comprises storing the received credential in the section of the memory unit for the stored credential to serve as the indication, and

after the second operating mode has been set, prohibiting a reset of the indication indicating that the second operating mode has been set and refusing access to a hardware unique key stored in the mobile device.

19. A mobile device, comprising:

an input device for receiving input information from a user of the mobile device,

an output device for outputting output information to the user, and

a processing unit adapted to:

receive via the input device a request from the user to change from a first operating mode of the mobile device to a second operating mode of the mobile device,

request a credential from the user in response to the received request,

receive a credential from the user,

validate the received credential, and

if the received credential is valid:

set the second operating mode,

set an indication of the mobile device indicating that the second operating mode has been set, wherein the indication relates to a section of a memory unit of the mobile device which has limited access, and wherein setting the indication comprises storing the received credential in the section of the memory unit for the stored credential to serve as the indication, and

after the second operating mode has been set, prohibit resetting the indication indicating that the second operating mode has been set and refuse access to a hardware unique key stored in the mobile device.