Transparent Code Authentication at the Processor Level

We present a lightweight authentication mechanism which verifies the authenticity of code and thereby addresses the virus and malicious code problems at the hardware level eliminating the need for trusted extensions in the operating system. The tech-nique we propose tightly integrates the authentication mechanism into the processor core. The authentication latency is hidden behind the memory access latency, thereby allowing seamless on-the-fly authentication of instructions. In addition, the proposed authentication method supports seamless encryption of code (and static data). Conse-quently, while providing the software users with assurance for authenticity of programs executing on their hardware, the proposed technique also protects the software man-ufacturers ’ intellectual property through encryption. The performance analysis shows that, under mild assumptions, the presented technique introduces negligible overhead for even moderate cache sizes