Semiconductor memory card, and program for controlling the same
First Claim
1. A semiconductor memory card comprising a tamper resistant module that is tamper resistant and a nonvolatile memory that is not tamper resistant,wherein the tamper resistant module includes:
- an internal memory having a usage area used by a program stored in the tamper resistant module; and
a processing unit including a virtual machine and an operation system, the program being an application executed by the virtual machine,wherein when requested by the program, the processing unit is operable to (i) assign an area in the nonvolatile memory that is not tamper resistant to the program, and (ii) generate, in the internal memory of the tamper resistant module, access information for the assigned area in the nonvolatile memory that is not tamper resistant,wherein the assigned area in the nonvolatile memory that is not tamper resistant is for a portion of confidential data to be written in, the portion of confidential data being used by the program and read by referring to the access information existing in the internal memory of the tamper resistant module,wherein the internal memory stores a first area table indicating a location and a size of the usage area,wherein the nonvolatile memory that is not tamper resistant stores a second area table indicating a location and a size of the assigned area in the nonvolatile memory that is not tamper resistant, the second area table being encrypted using a predetermined encryption key, andwherein the access information is a set of the predetermined encryption key and information indicating a location of the second area table.
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Accused Products
Abstract
A semiconductor memory card that has a sufficient storage capacity when an EC application writes data to a storage is provided. A usage area for the EC application in an EPPROM 3 in a TRM 1 is expanded. The expansion is such that a partition generated in a flash memory 2 outside the TRM 1 is assigned to the EC application while a partition table is allocated in the internal EEPROM 3. Because the partition table is in the TRM 1, only a CPU 7 in the TRM 1 is able to access the generated partition table. Secrecy of stored contents increases because the access to the expanded area is limited to the CPU 7 in the TRM 1.
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Citations
14 Claims
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1. A semiconductor memory card comprising a tamper resistant module that is tamper resistant and a nonvolatile memory that is not tamper resistant,
wherein the tamper resistant module includes: -
an internal memory having a usage area used by a program stored in the tamper resistant module; and a processing unit including a virtual machine and an operation system, the program being an application executed by the virtual machine, wherein when requested by the program, the processing unit is operable to (i) assign an area in the nonvolatile memory that is not tamper resistant to the program, and (ii) generate, in the internal memory of the tamper resistant module, access information for the assigned area in the nonvolatile memory that is not tamper resistant, wherein the assigned area in the nonvolatile memory that is not tamper resistant is for a portion of confidential data to be written in, the portion of confidential data being used by the program and read by referring to the access information existing in the internal memory of the tamper resistant module, wherein the internal memory stores a first area table indicating a location and a size of the usage area, wherein the nonvolatile memory that is not tamper resistant stores a second area table indicating a location and a size of the assigned area in the nonvolatile memory that is not tamper resistant, the second area table being encrypted using a predetermined encryption key, and wherein the access information is a set of the predetermined encryption key and information indicating a location of the second area table. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A controlling program in a semiconductor memory card that comprises a tamper resistant module and a nonvolatile memory that is not tamper resistant, and that is executed by a CPU in the tamper resistant module,
wherein the tamper resistant module includes: - an internal memory having a usage area used by an application stored in the tamper resistant module;
a virtual machine; and
an operation system, the application being executable by the virtual machine,wherein the controlling program is operable to (i) assign an area in the nonvolatile memory that is not tamper resistant to the application, and (ii) generate, in the internal memory of the tamper resistant module, access information for the assigned area in the nonvolatile memory that is not tamper resistant, wherein the assigned area in the nonvolatile memory that is not tamper resistant is for a portion of confidential data to be written in, the portion of confidential data being used by the program and read by referring to the access information existing in the internal memory of the tamper resistant module, wherein the internal memory stores a first area table indicating a location and a size of the usage area, wherein the nonvolatile memory that is not tamper resistant stores a second area table indicating a location and a size of the assigned area in the nonvolatile memory that is not tamper resistant, the second area table being encrypted using a predetermined encryption key, and wherein the access information is a set of the predetermined encryption key and information indicating a location of the second area table.
- an internal memory having a usage area used by an application stored in the tamper resistant module;
Specification