Semiconductor memory card and data reading apparatus

• US 20050005149A1
• Filed: 07/28/2004
• Published: 01/06/2005
• Est. Priority Date: 04/27/1999
• Status: Active Grant

• Current Assignee: Makoto Tatebayashi, Masataka Minami, Masayuki Kozuka, Taihei Yugawa, Teruto Hirota
• Original Assignee: Makoto Tatebayashi, Masataka Minami, Masayuki Kozuka, Taihei Yugawa, Teruto Hirota
• Inventors: Tatebayashi, Makoto, Kozuka, Masayuki, Minami, Masataka, Hirota, Teruto, Yugawa, Taihei
• Granted Patent: US 7,062,652 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 21/445 by mutual authentication, e.g. between devices or programs
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 21/78 to assure secure storage of data address-based protection against unauthorised use of memory G06F12/14; record carriers for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 2221/2105 Dual mode as a secondary aspect
• CPC Class Codes: G06Q 20/3674 involving authentication
• CPC Class Codes: G11C 16/22 Safety or protection circuits preventing unauthorised or accidental access to memory cells
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 9/3273 for mutual authentication network architectures or network communication protocols for achieving mutual authentication in a packet data network H04L63/0869
• CPC Class Codes: Y04S 40/20 Information technology specific aspects, e.g. CAD, simulation, modelling, system security

Abstract

A semiconductor memory card comprising a control IC 302, a flash memory 303, and a ROM 304. The ROM 304 holds information such as a medium ID 341 unique to the semiconductor memory card. The flash memory 303 includes an authentication memory 332 and a non-authentication memory 331. The authentication memory 332 can be accessed only by external devices which have been affirmatively authenticated. The non-authentication memory 331 can be accessed by external devices whether the external devices have been affirmatively authenticated or not. The control IC 302 includes control units 325 and 326, an authentication unit 321 and the like. The control units 325 and 326 control accesses to the authentication memory 332 and the non-authentication memory 331, respectively. The authentication unit 321 executes a mutual authentication with an external device.

Claims

1. A semiconductor memory card for use with an electronic device, said semiconductor memory card comprising:

a rewritable nonvolatile memory;

a device operable to hold information relating to an area size of said rewritable nonvolatile memory;

a control unit operable to control accesses by the electronic device to an authentication area and a non-authentication area in said rewritable nonvolatile memory; and

an area resizing unit operable to resize the authentication area and the non-authentication area, wherein said area resizing unit resizes the authentication area and the non-authentication area based on the information relating to the area size of said rewritable nonvolatile memory after deleting all contents of said rewritable nonvolatile memory,

wherein said control unit comprises;

an authentication unit operable to perform an authentication process to check whether the electronic device has authority to access said semiconductor memory card, and affirmatively authenticate the electronic device when the electronic device has authority to access said semiconductor memory card; and

an authentication area access control unit operable to permit the electronic device to access the authentication area only when said authentication unit affirmatively authenticates the electronic device, and

wherein the authentication area and the non-authentication area are provided by dividing a continuous area of a predetermined size in said rewritable nonvolatile memory into two parts.

2. A semiconductor memory card as claimed in claim 1, wherein the information relating to the area size of said rewritable nonvolatile memory includes a boundary marking address between the authentication area and the non-authentication area.

3. A semiconductor memory card as claimed in claim 2, further comprising:

a non-authentication area access control unit operable to control accesses by the electronic device to the non-authentication area,

wherein said authentication area access control unit and said non-authentication area access control unit control accesses by the electronic device to the authentication area and the non-authentication area by referring to the boundary marking address.

4. A semiconductor memory card as claimed in claim 1, wherein:

said authentication unit is operable to generate a key reflecting a result of the authentication process; and

said authentication area access control unit is operable to decrypt an encrypted instruction sent from the electronic device using the key generated by said authentication unit, and is operable to control accesses by the electronic device to the authentication area in accordance with the decrypted instruction.

5. A semiconductor memory card as claimed in claim 4, wherein said authentication unit is operable to perform a challenge-response type mutual authentication with the electronic device, and generate the key from challenge data and response data, the challenge data being sent to the electronic device to check whether the electronic device has authority to access said semiconductor memory card, and the response data being generated to indicate that said authentication unit has authority to access said semiconductor memory card.

6. A semiconductor memory card as claimed in claim 5, wherein:

the encrypted instruction sent from the electronic device includes a tag field and an address field, the tag field not being encrypted and specifying a type of an access to the authentication area, and the address field having been encrypted and specifying an address of an area to be accessed; and

said authentication area access control unit is operable to decrypt the address field using the key, and control accesses by the electronic device to the authentication area so that an access of the type specified in the tag field is made to the area indicated by the address in the decrypted address field.

7. A semiconductor memory card as claimed in claim 6, further comprising:

an identification data storage unit operable to prestore identification data which is unique to said semiconductor memory card and enables said semiconductor memory card to be discriminated from other semiconductor memory cards,

wherein said authentication unit is operable to perform a mutual authentication with the electronic device using the identification data stored in said identification data storage unit and generate the key from the identification data.

8. A semiconductor memory card as claimed in claim 1, further comprising:

a read-only memory unit operable to prestore data.

9. A semiconductor memory card as claimed in claim 1, wherein said control unit further comprises:

an encryption/decryption unit operable to encrypt data to be written to the authentication area and the non-authentication area and decrypt data read out from the authentication area and the non-authentication area.

10. A semiconductor memory card as claimed in claim 1, wherein said authentication unit is operable to request a user of the electronic device to input a user key during the authentication process, the user key being information unique to the user, and wherein said control unit further comprises:

a user key storage unit operable to store the user key;

an identification information storage unit operable to store a piece of identification information identifying an electronic device that has been affirmatively authenticated by said authentication unit; and

a user key request prohibition unit operable to obtain a piece of identification information from a target electronic device after said authentication unit starts the authentication process, check whether the piece of identification information obtained from the target electronic device has already been stored in said identification information storage unit, and prohibit said authentication unit from requesting a user of the electronic device to input a user key when the piece of identification information obtained from the target electronic device has already been stored in said identification information storage unit.

11. A data reading apparatus operable to readout digital content from a semiconductor memory card, the semiconductor memory card containing:

a rewritable nonvolatile memory;

an authentication area and a non-authentication area which are provided by dividing a continuous area of a predetermined size in the rewritable nonvolatile memory into two parts; and

an area resizing unit operable to resize the authentication area and the non-authentication area, wherein the area resizing unit resizes the authentication area and the non-authentication area based on information relating to an area size of the rewritable nonvolatile memory after deleting all contents of the rewritable nonvolatile memory,

wherein the digital content is stored in the non-authentication area of the semiconductor memory card and information indicating a number of times the digital content can be read out is prestored in the authentication area,

said data reading apparatus comprising;

a judgment device operable to, when the digital content is to be read out from the non-authentication area, read out the information indicating the number of times the digital content can be read out from the authentication area, and judge whether the digital content can be read out based on the number of times indicated in the information; and

a reproduction device operable to read out the digital content from the non-authentication area only when said judgment device judges that the digital content can be read out, and reduce the number of times the digital content can be read out in the information stored in the authentication area.

12. A data reading/reproducing apparatus operable to read out digital content from a semiconductor memory card and reproduce the read-out digital content as an analog signal, the semiconductor memory card containing:

a rewritable nonvolatile memory;

an authentication area and a non-authentication area which are provided by dividing a continuous area of a predetermined size in the rewritable nonvolatile memory into two parts; and

an area resizing unit operable to resize the authentication area and the non-authentication area, wherein the area resizing unit resizes the authentication area and the non-authentication area based on information relating to an area size of the rewritable nonvolatile memory after deleting all contents of said rewritable nonvolatile memory,

wherein the digital content, which can be reproduced as an analog signal, is stored in the non-authentication area of the semiconductor memory card and information indicating a number of times the digital content can be digitally output by the electronic device is stored in the authentication area,

said data reading/reproducing apparatus comprising;

a reproduction device operable to read out the digital content from the non-authentication area and reproduce the read-out digital content as an analog signal;

a judgment device operable to read out the information indicating the number of times the digital content can be digitally output by the electronic device, and judge whether the digital content can be digitally output based on the number of times indicated in the information; and

a digital output device operable to digitally output the digital content when said judgment device judges that the digital content can be digitally output, and reduce the number of times the digital content can be digitally output in the information stored in the authentication area.