METHOD AND PROGRAM FOR PROVIDING TAMPER RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a method for increasing security of software. SOLUTION: Tamper resistance is provided to prevent reading of an operation of a software part by calling functions which can be exclusively used by one distinguished section of a processor, its peripheral equipment and a driver from other distinguished section. Pseudo random binary sequence generators 110, 120 are related to each of such distinguished sections and each of them can be made incremental according to call and execution of the functions. Values of the pseudo random binary sequences are compared with each other before permitting or preventing further execution of the software. This comparison can be executed at all privileged levels and additional security is provided by using an additional privileged function to execute the comparison by modification of this invention.