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

• US 20030046570A1
• Filed: 08/05/2002
• Published: 03/06/2003
• Est. Priority Date: 08/07/2001
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Kiiveri, Antti, Sormunen, Toni, Jauhiainen, Antti, Ronkka, Risto
• Granted Patent: US 7,437,574 B2
• Time in Patent Office: Days
• US Class Current: 713/193
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 21/74 operating in dual or compartmented mode, i.e. at least one secure mode
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic

Abstract

Processing information in an electronic device is carried out by at least one processing block for controlling the operation of the electronic device, and a memory. At least a first private key is used for processing information. At least a protected mode and a normal mode are established in the processing block. Part of the memory can be accessed only in said protected mode. At least said first private key is stored in the memory that is accessible in said protected mode.

Claims

1. A method for processing information in an electronic device which comprises at least one processing block for controlling the operation of an electronic device and memory, and in which method at least a first private key is used for processing the information, wherein at least a protected mode and a normal mode are established in the processing block, that part of the memory is accessible only in said protected mode, and that information of at least said first private key is stored in the memory that is accessible in said protected mode.

2. The method according to claim 1, wherein in said protected mode the transfer of information from the processing block is prevented to prevent the determination of the internal function of the processing block.

3. The method according to claim 1, wherein at least one second private key is established in the electronic device, said second private key being encrypted with said first private key and stored in encrypted format in the memory that is accessible in an unprotected mode of the electronic device, wherein the second private key can be decrypted with said first private key.

4. The method according to claim 2, wherein the electronic device receives encrypted information, wherein to decrypt the encrypted information, said second private key is decrypted with said first private key, and the information is decrypted with said decrypted second private key.

5. The method according to claim 1, wherein when said first key is used, the processing block is set in said protected mode.

6. The method according to claim 1, wherein in the method an electronic device is authenticated, which electronic device contains at least a device identity stored therein, and at least one second private key which is encrypted with said first private key which entails at least one public key wherein at least the following steps are taken in the authentication:

decryption of said second private key,

forming a digital signature on the basis of said device identity to verify the authenticity of the device identity, in which said second private key is used, and

verifying said digital signature with said public key to identify the electronic device.

7. A system for processing information in an electronic device which comprises at least one processing block for controlling the operation of an electronic device and memory, and which system contains means for using at least a first private key for processing information, wherein at least a protected mode and a normal mode are established in the processing block, that the processing block comprises means for accessing part of the memory only in said protected mode, and that information of at least said first private key is stored in the memory that is accessible in said protected mode.

8. The system according to claim 7, wherein the processing block comprises means for preventing the transfer of information from outside the processing block in said protected mode, wherein the determination of the internal function of the processing block is prevented in the protected mode.

9. The system according to claim 7, wherein at least one second private key is established in the electronic device, said second private key being encrypted with said first private key and stored in encrypted format in the memory that is accessible in the unprotected mode of the electronic device, wherein the system comprises means for decrypting said second private key with said first private key.

10. The system according to claim 8, wherein the electronic device comprises means for receiving encrypted information, means for decrypting said second private key with said first private key, and means for decrypting the encrypted information with said second decrypted private key.

11. The system according to claim 7 comprising means for setting the processing block in said protected mode when said first key is used.

12. The system according to claim 7 comprising means for authenticating an electronic device, which electronic device contains the at least one device identity stored therein and at least one second private key which are encrypted with said first private key that entails at least one public key, wherein the system comprises means for decrypting said device identity and said second private key, means for forming a digital signature on the basis of said device identity to verify the authenticity of the device identity by using said second private key, and means for verifying said digital signature with said public key to authenticate the electronic device.

13. An electronic device that comprises means for processing information, at least one processing block for controlling the operation of an electronic device and a memory, and means for using at least a first private key for processing information, wherein at least a protected mode and a normal mode are established in the processing block, that the processing block comprises means for accessing part of the memory only in said protected mode, and that information of at least said first private key is stored in the memory that is accessible in said protected mode.

14. The electronic device according to claim 13, wherein at least a part of the memory used in said protected mode is a one time programmable read-only memory.

15. A processing block that comprises at least one processor, memory, and means for using at least a first private key for processing information, wherein at least a protected mode and normal mode are established in the processing block, that the processing block comprises means for accessing part of the memory only in said protected mode, and that information at least on said first private key is stored in the memory that is accessible in said protected mode.