The Importance of Entropy Source Validation in Common Criteria: Navigating the New Assurance Landscape (A31a)
The security of any cryptographic module fundamentally rests on the quality of its underlying random number generation. In recent years a greater emphasis is being placed on ensuring that entropy sources used to seed the cryptographic modules of a target of evaluation (TOE) are thoroughly examined and validated. As international frameworks evolve, the evaluation community is witnessing a decisive shift away from legacy Shannon entropy estimations toward rigorous min-entropy modeling, championed by international bodies such as the BSI. Furthermore, the era of relying on “passive entropy” claims has effectively ended; obtaining formal Entropy Source Validation (ESV) is now a mandatory baseline across major schemes, including FIPS 140-3. This paradigm shift is reflected directly in recent policy updates. Notably, NIAP released a Clarification to the Entropy Documentation and Assessment Annex: ESV certificates must be included as part of the Entropy Assessment Report (EAR) review for all products that are in evaluation with NIAP after January, 2025. This talk will explore the technical and procedural impacts of these hardened requirements on Common Criteria evaluations. The presenters will examine the practical challenges of validating complex, non-physical entropy designs, such as CPU Jitter RNGs, and the regulatory scrutiny applied to heuristic procedures, oversampling rates, and continuous health testing. By bridging the gap between deep statistical analysis and practical certification requirements, attendees will gain actionable insights into successfully navigating the updated entropy source validation process and ensuring robust cryptographic compliance in an increasingly stringent global landscape.