| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a processor apparatus for making it difficult to obtain and analyze data even if storing the data in the external memory of a control unit. <P>SOLUTION: The control unit includes: an encryption/decryption means which, when an access signal to the external memory designated by a CPU is used for writing, encrypts an address to generate a write address, and encrypts write data to generate encrypted data for writing, and which, when the access signal is used for reading, encrypts an address to generate a read address, and decrypts the encrypted data read from the external memory to generate plaintext data; and an external control means which writes the encrypted data for writing in a position designated by the write address generated by the encryption/decryption means, and which reads the encrypted data from a position designated by the read address generated by the encryption/decryption means, and supplies the encrypted data to the encryption/decryption means for its decryption. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
