Information storage device, memory access control system and method, and computer program

• US 20040215910A1
• Filed: 02/06/2004
• Published: 10/28/2004
• Est. Priority Date: 06/25/2002
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Okaue, Takumni, Nakanishi, Kenichi, Okubo, Hideaki, Tashiro, Jun
• Granted Patent: US 7,636,826 B2
• Time in Patent Office: Days
• US Class Current: 711/164
• CPC Class Codes: G06F 12/1466 Key-lock mechanism
• 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

Abstract

A device and method is provided for commonly and securely allowing, as access control on a memory card, a plurality of information processing apparatuses to lock/unlock the memory. On the basis of a lock command input from an information processing apparatus serving as a host, such as a PC, an information storage device, such as a memory card, determines whether (a) a standard lock key set serving as a key set prohibiting output or (b) an export lock key set serving as a key set permitting output is detected and stores corresponding key set information. Only when the export lock key set is detected, output is permitted provided that predetermined verification succeeds.

Claims

1. An information storage device comprising a memory for storing data and a controller for performing access control on the memory, wherein

the controller performs locking of the memory on the basis of a lock command and an identifier (ID) input from an information processing apparatus, and

the controller determines, on the basis of the lock command, whether a key set including the identifier (ID) is

(a) a standard lock key set serving as a key set prohibiting output, or

(b) an export lock key set serving as a key set permitting output, and

stores determination information in storage means.

2. The information storage device according to claim 1, wherein the information storage device stores lock status information in the storage means, the lock status information serving as determination information based on which the lock status of the information storage device is determined,

the lock status information includes information based on which it is determined whether the information storage device is standard-locked or export-locked, and

the controller outputs, on the basis of the lock status information, the export lock key set to the information processing apparatus provided that it is determined that the information storage device is export-locked.

3. The information storage device according to claim 1, wherein the controller determines whether it is permitted to output the export lock key set to the information processing apparatus, and

the determination includes verification of a key set unique to the information processing apparatus, which is input from the information processing apparatus, and the export lock key set is output to the information processing apparatus at least provided that the verification succeeds.

4. The information storage device according to claim 3, wherein the key set unique to the information processing apparatus is a primary key set [IDs, LKs] consisting of a primary ID (IDs) serving as a unique ID of the information processing apparatus and a primary lock key (LKs) serving as a lock key associated with the unique ID,

the information storage device has a lock master key (LMK) that is applicable to compute the primary lock key (LKs), which is a hash value based on the relationship LKs=H(LMK, IDs), the hash value being computed for the primary ID (IDs) by applying the lock master key (LMK), and

the controller verifies the key set unique to the information processing apparatus, which is input from the information processing apparatus, on the basis of a lock key (LK) obtained by computing the hash value by applying the lock master key (LMK).

5. The information storage device according to claim 4, wherein the controller generates a random number and receives, from the information processing apparatus, encrypted data [E(Lks, Rms)] generated by encrypting the random number (Rms) on the basis of the primary lock key (LKs) held by the information processing apparatus, and

the controller performs verification including checking of the received encrypted data against encrypted data [E(Lks, Rms)] computed on the basis of the primary lock key (LKs) obtained by computing the hash value.

6. The information storage device according to claim 1, wherein the information processing apparatus has, serving as a unique key set, a primary key set [IDs, LKs] consisting of a primary ID (IDs) serving as a unique ID of the information processing apparatus and a primary lock key (LKs) defined in association with the primary ID (IDs), and

in response to an export-lock-key-set output request from the information processing apparatus, the controller encrypts data of the export lock key set on the basis of the primary lock key (LKs) held by the information processing apparatus and outputs the encrypted data.

7. The information storage device according to claim 6, wherein the export lock key set is a sub key set [IDen, LKen] consisting of a data set of a sub ID (IDen) input from the information processing apparatus having performed export locking and a sub lock key (LKen) defined in association with the sub ID (IDen), and

the controller encrypts the sub lock key (LKen) on the basis of the primary lock key (LKs) held by the information processing apparatus having made a sub-key-set output request and outputs encrypted data [E(LKs, LKen)].

8. A memory access control system comprising an information storage device including a memory for storing data and a controller for performing access control on the memory and an information processing apparatus including an interface with the information storage device and accessing the memory in the information storage device via the interface,

wherein the information processing apparatus stores a key set including an identifier (ID) and a lock key (LK) in storage means,

the controller of the information storage device performs locking of the memory on the basis of a lock command and the identifier (ID) input from the information processing apparatus, the controller of the information storage device determines, on the basis of the lock command, whether the key set including the identifier (ID) is

(a) a standard lock key set serving as a key set prohibiting output, or

(b) an export lock key set serving as a key set permitting output, and

stores determination information in storage means, and

on the basis of the determination information, the controller of the information storage device determines whether it is permitted to output the key set to the information processing apparatus.

9. The memory access control system according to claim 8, wherein the information processing apparatus stores a primary key set [IDs, LKs] consisting of a primary ID (IDs) serving as a unique ID of the information processing apparatus and a primary lock key (LKs) serving as a lock key associated with the unique ID in the storage means,

the information storage device has a lock master key (LMK) that is applicable to compute the primary lock key (LKs), which is a hash value based on the relationship LKs=H(LMK, IDs), the hash value being computed for the primary ID (IDs) by applying the lock master key (LMK), and

the controller of the information storage device verifies a key set unique to the information processing apparatus, which is input from the information processing apparatus, on the basis of a lock key (LK) obtained by computing the hash value by applying the lock master key (LMK).

10. The memory access control system according to claim 8, wherein the controller of the information storage device generates a random number and receives, from the information processing apparatus, encrypted data [E(Lks, Rms)] generated by encrypting the random number (Rms) on the basis of a primary lock key (LKs) held by the information processing apparatus, and

the controller of the information storage device performs verification including checking of the received encrypted data against encrypted data [E(Lks, Rms)] computed on the basis of a primary lock key (LKs) obtained by computing a hash value.

11. The memory access control system according to claim 8, wherein the information processing apparatus has, serving as a unique key set, a primary key set [IDs, LKs] consisting of a primary ID (IDs) serving as a unique ID of the information processing apparatus and a primary lock key (LKs) defined in association with the primary ID (IDs), and

in response to an export-lock-key-set output request from the information processing apparatus, the controller of the information storage device encrypts data of the export lock key set on the basis of the primary lock key (LKs) held by the information processing apparatus and outputs the encrypted data, and

the information processing apparatus obtains the data of the export lock key set by decrypting the encrypted data on the basis of the primary lock key (LKs) held by the information processing apparatus.

12. The memory access control system according to claim 11, wherein the export lock key set is a sub key set [IDen, LKen] consisting of a data set of a sub ID (IDen) input from the information processing apparatus having performed export locking and a sub lock key (LKen) defined in association with the sub ID (IDen), and

the controller of the information storage device encrypts the sub lock key (LKen) on the basis of the primary lock key (LKs) held by the information processing apparatus having made a sub-key-set output request and outputs encrypted data [E(LKs, LKen)] to the information processing apparatus.

13. A memory access control method for an information storage device including a memory for storing data and a controller for performing access control on the memory, the method comprising:

a step of receiving a lock command and an identifier (ID) input from an information processing apparatus, and

a step of determining, on the basis of the lock command, whether a key set including the identifier (ID) is

(a) a standard lock key set serving as a key set prohibiting output, or

(b) an export lock key set serving as a key set permitting output, and

storing determination information in storage means.

14. The memory access control method according to claim 13, wherein the determination information is lock status information serving as lock-status determination information,

the lock status information includes information based on which it is determined whether the information storage device is standard-locked or export-locked, and

the memory access control method further comprises a step of outputting, on the basis of the lock status information, the export lock key set to the information processing apparatus provided that it is determined that the information storage device is export-locked.

15. The memory access control method according to claim 13, wherein, as determination of whether it is permitted to output the export lock key set to the information processing apparatus, verification is performed on a key set unique to the information processing apparatus, which is input from the information processing apparatus, and the export lock key set is output to the information processing apparatus at least provided that the verification succeeds.

16. The memory access control method according to claim 15, wherein the key set unique to the information processing apparatus is a primary key set [IDs, LKs] consisting of a primary ID (IDs) serving as a unique ID of the information processing apparatus and a primary lock key (LKs) serving as a lock key associated with the unique ID,

the information storage device has a lock master key (LMK) that is applicable to compute the primary lock key (LKs), which is a hash value based on the relationship LKs=H(LMK, IDs), the hash value being computed for the primary ID (IDs) by applying the lock master key (LMK), and

the verification includes a step of verifying the key set unique to the information processing apparatus, which is input from the information processing apparatus, on the basis of a lock key (LK) obtained by computing the hash value by applying the lock master key (LMK).

17. The memory access control method according to claim 16, wherein the verification step includes a step of generating a random number, receiving, from the information processing apparatus, encrypted data [E(Lks, Rms)] generated by encrypting the random number (Rms) on the basis of the primary lock key (LKs) held by the information processing apparatus, and

performing verification including checking of the received encrypted data against encrypted data [E(Lks, Rms)] computed on the basis of the primary lock key (LKs) obtained by computing the hash value.

18. The memory access control method according to claim 13, wherein the information processing apparatus has, serving as a unique key set, a primary key set [IDs, LKs] consisting of a primary ID (IDs) serving as a unique ID of the information processing apparatus and a primary lock key (LKs) defined in association with the primary ID (IDs), and

the memory access control method further comprises an encryption and output step of encrypting, in response to an export-lock-key-set output request from the information processing apparatus, data of the export lock key set on the basis of the primary lock key (LKs) held by the information processing apparatus and outputting the encrypted data.

19. The memory access control method according to claim 18, wherein the export lock key set is a sub key set [IDen, LKen] consisting of a data set of a sub ID (IDen) input from the information processing apparatus having performed export locking and a sub lock key (LKen) defined in association with the sub ID (IDen), and

the encryption and output step is a step of encrypting the sub lock key (LKen) on the basis of the primary lock key (LKs) held by the information processing apparatus having made a sub-key-set output request and outputting encrypted data [E(LKs, LKen)].

20. A computer program for performing memory access control on an information storage device including a memory for storing data and a controller for performing access control on the memory, the program comprising:

a step of receiving a lock command and an identifier (ID) input from an information processing apparatus, and

a step of determining, on the basis of the lock command, whether a key set including the identifier (ID) is

(a) a standard lock key set serving as a key set prohibiting output, or

(b) an export lock key set serving as a key set permitting output, and

storing determination information in storage means.