Quantifying hardware security using joint information flow analysis

Existing hardware design methodologies provide limited methods to detect security flaws or derive a measure on how well a mitigation technique protects the system. Information flow analysis provides a powerful method to test and verify a design against security properties that are typically expressed using the notion of noninterference. While this is useful in many scenarios, it does have drawbacks primarily related to its strict enforcement of limiting all information flows - even those that could only occur in rare circumstances. Quantitative metrics based upon information theoretic measures provide an approach to loosen such restrictions. Furthermore, they are useful in understanding the effectiveness of security mitigations techniques. In this work, we discuss information flow analysis using noninterference and qualitative metrics. We describe how to use them in a synergistic manner to perform joint information flow analysis. And we use this novel technique to analyze security properties across several different hardware cryptographic cores.