Electronic apparatus and control method thereof
AssigneeKabushiki Kaisha Toshiba
InventorsTatsuo Yamaguchi, Yuki Kanbe
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Abstract
According to one embodiment, an electronic apparatus includes a processor configured to operate based on a clock, the processor includes a register in which a value added in accordance with the clock is stored, and a memory configured to store first period information indicating a first period in which a file is accessible. The processor is configured to acquire first time and date information indicating a first time and date from an external device, calculate a second time and date indicating a present time and date based on the first time and date information and the value, and restrict access to a resource of the electronic apparatus, when the second time and date does not correspond to the first period.
Claims8
An electronic apparatus comprising:
- a processor configured to operate based on a clock and to execute various applications including a file restriction application;
- and
- a nonvolatile memory in which a security policy and a file to which access is restricted in accordance with the security policy are stored,
- wherein the processor is configured to:
- record that the electronic apparatus is in a first state, when the file to which access is restricted is stored in the nonvolatile memory and a secure time is periodically acquirable from an external device;
- restrict access to the file in accordance with the security policy, if it is determined that the time when it is recorded that the electronic apparatus is in the first state is not during an available period of the first state when the electronic apparatus receives an access request to open the file;
- record that the electronic apparatus is in a second state, when the file to which access is restricted is stored in the nonvolatile memory and the secure time is not acquirable from the external device;
- and
- restrict access to the file in accordance with the security policy, if the electronic apparatus is in the second state when the electronic apparatus is restarted after being shut down and receives the access request to open the file, and if it is determined that a grace period is not during an available period of the grace period, the grace period being a period from when the electronic apparatus is set to power-on from power-off.
A control method of an electronic apparatus comprising a processor which is configured to operate based on a clock and to execute various applications including a file restriction application, and a nonvolatile memory in which a security policy and a file to which access is restricted in accordance with the security policy are stored, the method comprising:
- recording that the electronic apparatus is in a first state, when the file to which access is restricted is stored in the nonvolatile memory and a secure time is periodically acquirable from an external device;
- restricting access to the file in accordance with the security policy, if it is determined that the time when it is recorded that the electronic apparatus is in the first state is not during an available period of the first state when the electronic apparatus receives an access request to open the file;
- recording that the electronic apparatus is in a second state, when the file to which access is restricted is stored in the nonvolatile memory and the secure time is not acquirable from the external device;
- and
- restricting access to the file in accordance with the security policy, if the electronic apparatus is in the second state when the electronic apparatus is restarted after being shut down and receives the access request to open the file, and if it is determined that a grace period is not during an available period of the grace period, the grace period being a period from when the electronic apparatus is set to power-on from power-off.
A non-transitory computer-readable storage medium having stored thereon a computer program which is executable by a computer which comprises a processor which is configured to operate based on a clock and to execute various applications including a file restriction application, and a nonvolatile memory in which a security policy and a file to which access is restricted in accordance with the security policy are stored, the computer program comprising instructions capable of causing the computer to execute functions of:
- recording that the electronic apparatus is in a first state, when the file to which access is restricted is stored in the nonvolatile memory and a secure time is periodically acquirable from an external device;
- restricting access to the file in accordance with the security policy, if it is determined that the time when it is recorded that the electronic apparatus is in the first state is not during an available period of the first state when the electronic apparatus receives an access request to open the file;
- recording that the electronic apparatus is in a second state, when the file to which access is restricted is stored in the nonvolatile memory and the secure time is not acquirable from the external device;
- and
- restricting access to the file in accordance with the security policy, if the electronic apparatus is in the second state when the electronic apparatus is restarted after being shut down and receives the access request to open the file, and if it is determined that a grace period is not during an available period in the grace period, the grace period being a period from when the electronic apparatus is set to power-on from power-off.
Dependencies are inferred from the claim text.