| 摘要 |
PROBLEM TO BE SOLVED: To provide a program protection system and a security chip for increasing a resistance force against each kind of cipher analyzing method to illegally use a program, and for preliminarily preventing the illegal copy of a program or the duplication, forgery, and alteration of a substrate. SOLUTION: At the time of checking that a program to be executed is legal, a time interval for executing check is controlled. For example, a random number is generated, and the random number is encoded, and the encoded result is decoded, and the decoded result is compared with the generated random number, and when they are not made coincident, a stop signal for stopping the executing operation of the program is outputted in this system. Then, a time interval for executing the encoding processing is controlled so that any illegal analyzer can be prevented from obtaining the large number of input and output data of an encoder 104. |
