Encryption device, encryption system including the encryption device, decryption device and a semiconductor system including the decryption device
First Claim
1. An encryption device for encrypting confidential information in an external memory for storing instruction codes and data for controlling a semiconductor device and the confidential information to be a subject of protection against information leakage, the semiconductor device and the external memory together composing a semiconductor system, the encryption device comprising:
- a code conversion device for converting the confidential information into the instruction codes and storing in the external memory the confidential information as dummy instruction codes.
2 Assignments
0 Petitions
Accused Products
Abstract
A data/code conversion device receives confidential information, converts the confidential information into instruction codes for making a CPU provided in a semiconductor device perform its operation, and stores the instruction codes as dummy instruction codes in an external memory. One of the confidential information of which corresponding instruction code does not exist is converted into another instruction code as a dummy instruction code and stored, and correction data for reconstructing the confidential information from the instruction code is also stored in the external memory. In the semiconductor device, a decryption circuit for receiving the dummy instruction codes and the correction data stored in the external memory and performing decryption to obtain the confidential information is provided. Therefore, leakage of confidential information stored in the external memory can be reliably prevented with a relatively simple structure, so that the security level is increased.
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Citations
21 Claims
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1. An encryption device for encrypting confidential information in an external memory for storing instruction codes and data for controlling a semiconductor device and the confidential information to be a subject of protection against information leakage,
the semiconductor device and the external memory together composing a semiconductor system, the encryption device comprising: a code conversion device for converting the confidential information into the instruction codes and storing in the external memory the confidential information as dummy instruction codes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A decryption device in a semiconductor system,
the semiconductor system including a semiconductor device and an external memory, the external memory storing instruction codes and data for controlling the semiconductor device and dummy instruction codes obtained by encrypting confidential information to be a subject of protection against information leakage, wherein the decryption device reads out the dummy instruction codes from the external memory and decrypts the dummy instruction codes into the confidential information.
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12. A semiconductor system comprising:
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a semiconductor device;
an external memory which stores instruction codes and data for controlling the semiconductor device and dummy instruction codes obtained by encrypting confidential information to be a subject of protection against information leakage; and
a decryption device, provided in the semiconductor device, for reading out the dummy instruction codes from the external memory and decrypting the dummy instruction codes into the confidential information.
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Specification