| 摘要 |
Cryptoprocessor, comprising a processor core for receiving and implementing instructions of a program code based on a program flow chart, a program memory unit which stores the program code with instructions in an individually encrypted format, wherein the respective instructions contain at least one instruction data word and an instruction data key allocated to the respective instruction, a respective instruction is encrypted using a program data key and the instruction data key of a respective preceding instruction, which is to be implemented immediately before according to the program flow chart, and wherein, only in the event that a corresponding instruction in the program flow chart has a plurality of possible preceding instructions, the same instruction data key is allocated to the corresponding possible preceding instructions, but the respective instruction data keys are otherwise unique to the instruction; and a decryption unit, which is configured to receive the encrypted instructions from the program memory unit and to decrypt a respective received encrypted instruction using the program data key and the instruction data key of the corresponding preceding instruction, to transfer the thus currently decrypted at least one instruction data word of the instruction to the processor core for implementing the instruction, as well as to have the thus currently decrypted instruction data key available to be used in the decryption of the next received encrypted instruction. |
