Secure computer system having privileged and unprivileged memories

摘要

The microprocessor resides along with its protected real address space in a secure module surrounded by tamper resistant circuitry pad. Encryption programs and encryption keys are stored in the protected memory. A second real address space is also connected to the address and data bus of the microprocessor in order to provide program and data space for a user. Gating circuitry prevent the exposure of instructions and data form the privileged memory from appearing outside of the secure module. The gating circuits switch address spaces by recognizing a sequence of predetermined addresses.