Method for processing audiovisual information in an electronic device, a system, and an electronic device

• US 20030005322A1
• Filed: 06/27/2002
• Published: 01/02/2003
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Kiiveri, Antti
• Granted Patent: US 7,363,511 B2
• Time in Patent Office: Days
• US Class Current: 713/193
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/72 in cryptographic circuits
• CPC Class Codes: G06F 21/82 Protecting input, output or interconnection devices
• CPC Class Codes: G06F 2221/2105 Dual mode as a secondary aspect

Abstract

The invention relates to a method for processing audiovisual information in an electronic device comprising at least one control block for controlling the operation of the electronic device, and a memory. The audiovisual information is encrypted. The control block is provided with a protected processing block, and part of the memory is available in said protected processing block only. The audiovisual information is decrypted in said protected processing block and transmitted from the protected processing block to means for presenting audiovisual information.

Claims

1. A method for processing audiovisual information in an electronic device which comprises at least one control block for controlling the operation of an electronic device and a memory, wherein the audiovisual information is encrypted, that the control block is provided with a protected processing block, that a part of the memory is only available in said protected processing block, that the audiovisual information is decrypted in said protected processing block, and the audiovisual information is transmitted from the protected processing block to means for presenting audiovisual information.

2. The method according to claim 1, wherein in the electronic device, audiovisual information is processed in unencrypted format in said protected processing block only.

3. The method according to claim 1, wherein the electronic device is provided with at least a device-specific key, by which the encrypted audiovisual information is decrypted.

4. The method according to claim 3, wherein a public key is provided to correspond to said device-specific key, for encrypting audiovisual information intended to be presented in the electronic device.

5. The method according to claim 3, wherein said device-specific key is stored in the electronic device at the stage of manufacture of the electronic device.

6. The method according to claim 1, wherein at least the following steps are performed:

forming at least a device-specific key and a corresponding public key;

storing said device-specific key in the electronic device;

forming a pair of keys comprising a first key to be used for encrypting audiovisual information and a second key to be used for decrypting audiovisual information encrypted with the first key;

encrypting the second key of said pair of keys with said public key;

transmitting the encrypted second key of the pair of keys to the electronic device, in which the second key is decrypted with said secret key, wherein the audiovisual information is decrypted in the electronic device with said decrypted second key of the pair of keys.

7. The method according to claim 1, wherein at least the following steps are performed:

forming at least a device-specific key and a corresponding public key;

storing said device-specific key in the electronic device;

forming an encryption key to be used for encrypting and decrypting audiovisual information;

encrypting said encryption key with said public key;

transmitting the encrypted encryption key to the electronic device, in which the encryption key is decrypted with said device-specific key, wherein the audiovisual information is decrypted in the electronic device with said decrypted encryption key.

8. The method according to claim 1, wherein said protected processing block is provided with a digital-to-analog converter, by which the decrypted audio information is converted to an analog audio signal.

9. The method according to claim 1, wherein, outside said protected processing block, a digital-to-analog converter is provided, by which the decrypted audio information is arranged to be converted to an analog audio signal.

10. The method according to claim 1, wherein said protected processing block is provided with means for controlling the display, by which the decrypted visual information is converted to control signals for the display.

11. A system for processing audiovisual information in an electronic device comprising at least one control block for controlling the operation of the electronic device, a memory, and means for presenting audiovisual information, wherein the system comprises means for encrypting audiovisual information;

that the electronic device is provided with a protected processing block;

that the protected processing block comprises means for using a part of the memory only in said protected mode;

means for decrypting audiovisual information; and

that the electronic device comprises means for transmitting audiovisual information from the protected processing block to the means for presenting audiovisual information.

12. The system according to claim 11, wherein the electronic device comprises means for arranging audiovisual information to be processed in unencrypted format in said protected processing block only.

13. The system according to claim 11, wherein the electronic device is provided with at least a device-specific key, by which the encrypted audiovisual information is arranged to be decrypted.

14. The system according to claim 13, wherein the system comprises means for forming a public key corresponding to said device-specific key, whereby audiovisual information intended to be presented in the electronic device is arranged to be encrypted.

15. The system according to claim 13, wherein said device-specific key has been stored in the electronic device at the stage of manufacture of the electronic device.

16. The system according to claim 11 comprising at least:

a device-specific key and a corresponding public key, and which device-specific key is stored in the electronic device;

a pair of keys comprising a first key to be used for encryption of audiovisual information and a second key to be used for decrypting audiovisual information encrypted with the first key,

means for encrypting the second key of said pair of keys with said public key,

means for transmitting the encrypted second key of the pair of keys to the electronic device which comprises means for decrypting the second key with said secret key, and means for decrypting audiovisual information with said decrypted second key of the pair of keys.

17. The system according to claim 11 comprising at least:

a device-specific key and a corresponding public key, and which device-specific key is stored in the electronic device;

an encryption key to be used for the encryption of audiovisual information and for the decryption of encrypted audiovisual information,

means for encrypting said encryption key with said public key,

means for transmitting the encrypted encryption key to the electronic device which comprises means for decrypting the encryption key with said secret key, and means for decrypting audiovisual information with said decrypted encryption key.

18. The system according to claim 11, wherein said protected processing block comprises a digital-to-analog converter, by which the decrypted audio information is converted to an analog audio signal.

19. The system according to claim 11, wherein the electronic device comprises a digital-to-analog converter which is provided outside said protected processing block and by which the decrypted audio information is arranged to be converted to an analog audio signal.

20. The system according to claim 11, wherein said protected processing block comprises means for controlling the display, by which the decrypted audio information is converted to control signals for the display.

21. The system according to claim 11 comprising means for making payment transactions, and means for encrypting visual information related to the payment transaction to be transmitted to the electronic device.

22. An electronic device comprising at least one control block for controlling the operation of the electronic device, a memory, and means for presenting audiovisual information, wherein the electronic device comprises means for processing encrypted audiovisual information, that the electronic device is provided with a protected processing block;

that the protected processing block comprises means for using a part of the memory only in said protected mode;

means for decrypting audiovisual information; and

that the electronic device comprises means for transmitting audiovisual information from the protected processing block to the means for presenting audiovisual information.

23. The electronic device according to claim 22, wherein the electronic device is provided with at least a device-specific key, by which the encrypted audiovisual information is arranged to be decrypted.

24. The electronic device according to claim 22, wherein the electronic device is provided with at least a device-specific key, by which the key used for decrypting the encrypted audiovisual information is arranged to be decrypted.

25. An electronic device according to claim 22 comprising means for performing mobile station functions.