MEMORY CARD, APPLICATION PROGRAM HOLDING METHOD, AND HOLDING PROGRAM

• US 20090070599A1
• Filed: 04/28/2006
• Published: 03/12/2009
• Est. Priority Date: 05/09/2005
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Kawahara, Eiji, Kashiwabara, Kazuyuki, Nishimura, Yoshiko
• Granted Patent: US 7,953,985 B2
• Time in Patent Office: Days
• US Class Current: 713/193
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/3552 Downloading or loading of personalisation data
• CPC Class Codes: G06Q 20/3558 Preliminary personalisation for transfer to user
• CPC Class Codes: G06Q 20/40975 using encryption therefor
• CPC Class Codes: G07F 7/082 Features insuring the integrity of the data on or in the card
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system

Abstract

A memory card of the present invention is a memory card which receives an encrypted application program from a host apparatus, the encrypted application program being downloaded to the host apparatus, the memory card including: an Integrated Circuit (IC) card unit having a tamper resistant function; and a flash memory unit, wherein the IC card unit includes: a tamper resistant storage unit; a program acquisition unit which acquires the encrypted application program from the host apparatus; a storage control unit which stores the acquired encrypted application program in the tamper resistant storage unit or the flash memory unit; and a move control unit which, when the application program stored in the tamper resistant storage unit is to be executed and the size of the to-be-executed application program in the decrypted form exceeds the size of free space of the tamper resistant storage unit, moves an arbitrary encrypted application program stored in the tamper resistant storage unit to the flash memory unit.

Claims

1. A memory card which receives an encrypted application program from a host apparatus, the encrypted application program being downloaded to the host apparatus, said memory card comprising:

an Integrated Circuit (IC) card unit having a tamper resistant function; and

a flash memory unit,

wherein said IC card unit includes;

a tamper resistant storage unit;

a program acquisition unit operable to acquire, from the host apparatus, the encrypted application program and respective sizes of the application program in encrypted and decrypted forms;

a storage control unit operable to select one of said tamper resistant storage unit and said flash memory unit as a storage location area on the basis of the size of the acquired application program in the encrypted form and a size of free space of said tamper resistant storage unit, and to store the acquired encrypted application program in the selected storage location area;

a move control unit operable to, when the application program stored in said tamper resistant storage unit is to be executed and the size of the to-be-executed application program in the decrypted form exceeds the size of the free space of said tamper resistant storage unit, move an arbitrary encrypted application program stored in said tamper resistant storage unit to said flash memory unit; and

an execution unit operable to decrypt and execute the to-be-executed application program.

2. The memory card according to claim 1,

wherein, when the size of the acquired application program in the encrypted form is equal to or smaller than the size of the free space of said tamper resistant storage unit, said storage control unit is operable to store the application program in said tamper resistant storage unit, and when the size in the encrypted form exceeds the size of the free space, said storage control unit is operable to store the application program in said flash memory unit.

3. The memory card according to claim 2,

wherein, when the size of the acquired application program in the encrypted form exceeds the size of the free space of said tamper resistant storage unit, said storage control unit is operable to move an arbitrary encrypted application program stored in said tamper resistant storage unit to said flash memory unit.

4. The memory card according to claim 1,

wherein said execution unit is operable to move the to-be-executed encrypted application program to said flash memory unit after executing the application program.

5. The memory card according to claim 1,

wherein, when the to-be-executed application program is stored in said flash memory unit and a total of the respective sizes of the to-be-executed application program in the encrypted and decrypted forms exceeds the size of the free space of said tamper resistant storage unit, said move control unit is operable to move an arbitrary encrypted application program stored in said tamper resistant storage unit to said flash memory unit and to copy the to-be-executed application program to said tamper resistant storage unit.

6. The memory card according to claim 1,

wherein, when the to-be-executed application program is stored in said flash memory unit and the size of the to-be-executed application program in the decrypted form exceeds the size of the free space of said tamper resistant storage unit, said move control unit is operable to move an arbitrary encrypted application program stored in said tamper resistant storage unit to said flash memory unit, and to store the to-be-executed application program in said tamper resistant storage unit after decrypting the to-be-executed application program.

7. The memory card according to claim 1,

wherein said move control unit is operable to generate access history management information for each application program, on the basis of an execution history of the application program, and

said IC card unit further includes a move judgment unit operable to determine which application program is to be moved to said flash memory unit, in accordance with the access history management information.

8. The memory card according to claim 1,

wherein said program acquisition unit is operable to acquire information unique to the host apparatus,

said IC card unit further includes:

a key generation unit operable to generate an encryption key using the acquired information unique to the host apparatus; and

an additional encryption unit operable to encrypt the application program to be moved from said tamper resistant storage unit to said flash memory unit, using the encryption key, and

said move control unit is operable to erase the encryption key after the encryption, and to move the to-be-moved application program which is doubly encrypted with the encryption key to said flash memory unit.

9. The memory card according to claim 8,

wherein said IC card unit further includes

an additional decryption unit operable to, when the application program stored in said flash memory unit and doubly encrypted with the encryption key is copied to said tamper resistant storage unit, decrypt the to-be-copied application program using the encryption key generated by said key generation unit, and

said move control unit is operable to erase the encryption key after the decryption, and to store the to-be-copied application program in said tamper resistant storage unit.

10. An application program holding method for a memory card which receives an encrypted application program from a host apparatus, the encrypted application program being downloaded to the host apparatus,

wherein the memory card includes:

an Integrated Circuit (IC) card unit having a tamper resistant function; and

a flash memory unit, said IC card unit including a tamper resistant storage unit, and

the method comprises;

a program acquisition step of acquiring, from the host apparatus, the encrypted application program and respective sizes of the application program in encrypted and decrypted forms;

a storage control step of selecting one of the tamper resistant storage unit and the flash memory unit as a storage location area on the basis of the size of the acquired application program in the encrypted form and a size of free space of the tamper resistant storage unit, and storing the acquired encrypted application program in the selected storage location area;

a move control step of, when the application program stored in the tamper resistant storage unit is to be executed and the size of the to-be-executed application program in the decrypted form exceeds the size of the free space of the tamper resistant storage unit, moving an arbitrary encrypted application program stored in the tamper resistant storage unit to the flash memory unit; and

an execution step of decrypting and executing the to-be-executed application program.

11. An application program holding program for a memory card which receives an encrypted application program from a host apparatus, the encrypted application program being downloaded to the host apparatus,

wherein the memory card includes:

an Integrated Circuit (IC) card unit having a tamper resistant function; and

a flash memory unit, the IC card unit including a tamper resistant storage unit, and

said holding program causes a computer to execute;

a program acquisition step of acquiring the encrypted application program and respective sizes of the application program in encrypted and decrypted forms;

a storage control step of selecting one of the tamper resistant storage unit and the flash memory unit as a storage location area on the basis of the size of the acquired application program in the encrypted form and a size of free space of the tamper resistant storage unit, and storing the acquired encrypted application program in the selected storage location area;

a move control step of, when the application program stored in the tamper resistant storage unit is to be executed and the size of the to-be-executed application program in the decrypted form exceeds the size of the free space of the tamper resistant storage unit, moving an arbitrary encrypted application program stored in the tamper resistant storage unit to the flash memory unit; and

an execution step of decrypting and executing the to-be-executed application program.