| 摘要 |
PROBLEM TO BE SOLVED: To provide an information processor, which possesses data confidentiality retaining function, making interception of coded data difficult, by making the power consumption at read of key data at code processing or at operation of a cipher circuit constant, so that it will not change by the value of the key data, and making the inference of the key data difficult. SOLUTION: The key data, used for the code processing for data confidentiality retention, are stored in an E2PROM 14 together with its inverted data, and the key data and the inverted data are read out of the E2PROM, and based on the key data among them, a code-processing program is executed in a cipher circuit 5, and using the execution result, a computation program is executed in CPU 1. |
