System integrated circuit
First Claim
1. A system integrated circuit that is incorporated into an apparatus together with a memory device, the memory device storing confidential data, the system integrated circuit comprising:
- a central processing unit;
an access unit for reading and writing to and from the memory device;
an indication unit for performing an indication operation at initialization of the apparatus, the indication operation indicating to the central processing unit to start up; and
a read control unit for performing a read control operation, the read control operation controlling the access unit to read the confidential data from the memory device, wherein the read control operation performed by the read control unit precedes the indication operation performed by the indication unit.
1 Assignment
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Accused Products
Abstract
A system integrated circuit prevents a storage region of confidential data that has been read from a memory device from being revealed by tracing the operation of an internal CPU. The confidential data is stored in a secondary memory and is used by the CPU. The confidential data is read from the secondary memory to a primary memory at initialization of an apparatus in which the system integrated circuit is incorporated. Specifically, an initial-state management unit (15) reads the confidential data from the memory devices (101 or 111), and stores it into one of storage regions in the primary memory at the initialization of the apparatus. The initial-state management unit (15) then instructs the CPU to start its operation. Even if thorough reverse analysis is performed on the operation of the CPU, the storage region of the confidential data is not revealed.
19 Citations
13 Claims
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1. A system integrated circuit that is incorporated into an apparatus together with a memory device, the memory device storing confidential data, the system integrated circuit comprising:
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a central processing unit;
an access unit for reading and writing to and from the memory device;
an indication unit for performing an indication operation at initialization of the apparatus, the indication operation indicating to the central processing unit to start up; and
a read control unit for performing a read control operation, the read control operation controlling the access unit to read the confidential data from the memory device, wherein the read control operation performed by the read control unit precedes the indication operation performed by the indication unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A system integrated circuit that is connected to a memory device, the memory device storing confidential data and a program that includes a plurality of instructions, the system integrated circuit comprising:
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a central processing unit for sequentially reading and decoding the instructions included in the program; and
a storage unit having a plurality of storage regions;
wherein the program includes a first instruction to read the confidential data and a second instruction to perform processing using the confidential data, the first instruction preceding the second instruction, and the system integrated circuit further comprises a read unit for reading the confidential data from the memory device and writing the read confidential data to a predetermined one of the storage regions, when the first instruction is decoded by the central processing unit.
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Specification