Processor Security via Dynamic Instruction Encoding and Secure Zones

The patent applies dynamics by making the instruction encoding dynamic rather than static. The encoding of instructions changes at runtime based on secure zone boundaries and randomization, so that the same instruction can have different encodings at different times or in different contexts. This dynamic encoding prevents reverse engineering and side-channel attacks while maintaining operational functionality through the use of decode logic that adapts to the current encoding scheme.

The patent changes the encoding parameters of instructions randomly and uniquely for each secure zone. Instead of using fixed encoding schemes, the system varies the encoding parameters (such as opcode mappings, operand formats, and instruction length) based on the secure zone context and randomization seeds. This parameter variation makes it infeasible to extract meaningful information through traditional reverse engineering or power analysis techniques.

The patent segments the processor into multiple secure zones, each with its own randomized encoding scheme. By dividing the instruction stream into discrete secure zones with boundaries, the system can apply different encoding randomization to each zone while maintaining overall functionality. This segmentation approach makes the manufacturing complexity manageable by localizing the randomization logic to specific zones rather than requiring system-wide complexity.

The patent introduces intermediary decode logic that acts as a mediator between the randomized instruction encoding and the underlying processor execution units. This intermediary layer handles the complexity of decoding randomized instructions and translating them into standard internal operations, thereby isolating the manufacturing complexity to a dedicated decode stage rather than propagating it throughout the entire processor design.

The patent performs preliminary actions by pre-establishing secure zone boundaries and encoding schemes during system initialization or compilation. The randomized encoding parameters for each secure zone are determined in advance, allowing the processor to efficiently switch between predefined encoding schemes without requiring complex runtime generation. This preliminary preparation reduces the overhead during actual instruction execution and maintains processing speed.

The patent implements periodic action by organizing instructions into discrete secure zones with clear boundaries. Each secure zone represents a periodic unit of execution with its own encoding scheme. The processor transitions between zones in a periodic manner, resetting or changing encoding parameters at zone boundaries. This periodic structure allows for efficient pipeline management and minimizes the performance impact of encoding changes.

The patent extracts the encoding function from the execution function, creating a separate decode stage that handles all encoding randomization and obfuscation. By taking out the encoding complexity into a dedicated decode component, the execution units can operate with standard, simplified instructions. This extraction reduces the complexity of the execution path while maintaining security through the specialized decode layer that handles randomized encodings.

The patent uses copying by maintaining multiple copies of decode logic or encoding tables that correspond to different secure zones and randomization schemes. Instead of having a single complex decode unit that handles all possible encodings, the system uses multiple simpler decode copies, each optimized for specific encoding schemes. This copying approach distributes the complexity across multiple identical or similar components rather than concentrating it in a single complex unit.