SYSTEM ZUR SICHEREN CHIFFRIERSCHLÜSSELVERARBEITUNG

摘要

A system and method for storing encrypter keys in a secure manner to prevent a "debugger" or an unauthorized user of a user application from compromising the keys. A static RAM with a battery support is used to store the keys after they are installed therein by a processor included in the system. As used, the RAM because a write only RAM as far as the processor is concerned. Anytime a clear text key appears on a bus connecting the RAM with an enciphering chip used in the system, an interface between the bus and the processor is used to uncouple the bus from the processor. The system can also be used for "key encrypting key schemes".