Secure computing device

摘要

A secure computing system (100) stores a program, preferably the real time operating system (210), that is encrypted with a private key. A boot ROM (135) on the same integrated circuit as the data processor and inaccessible from outside includes an initialization program and a public key corresponding to the private key. On initialization the boot ROM decrypts at least a verification portion of the program. On verification normal operation is enabled. On non-verification, the system could be disabled, or that application program could be disabled. A diagnostic program is stored at predetermined non-relocatable physical address in memory. The program is made non-relocatable using a special table look-aside buffer (137) having a fixed virtual address register (611) and a corresponding fixed physical address register (641). The secure computing system prevents unauthorized use of compressed video data stored in a first-in-first-out memory buffer by encrypting the compressed video data stream using at least a part of the chip identity number as an encryption key (703). The data is recalled from memory (705) and decrypted (706) as needed for video decompression. The debugger/emulator tool commonly employed in program development is protected by a private encryption key used to encrypt at least verification token for the program. Upon each initialization of the debugger/ emulator, the secure computer system decrypts the verification token employing public decryption key (805) to indicate whether the program is secure or non-secure.