Quantum Encryption Resilience Score (QERS): A System-Level Evaluation Framework

The transition to post-quantum cryptography (PQC) presents significant challenges for modern computing environments due to increased computational overhead, communication latency, and implementation complexity. Existing evaluation methods typically focus on isolated cryptographic performance metrics and do not provide a unified framework for assessing the overall resilience of PQC deployments across heterogeneous systems. This paper introduces the Quantum Encryption Resilience Score (QERS), a novel system-level evaluation framework designed to quantify the resilience of post-quantum cryptographic implementations by integrating computational, network, and operational performance metrics into a single composite score. QERS provides a standardized methodology for comparing PQC algorithms across diverse deployment scenarios. In this study, the framework is experimentally evaluated using a heterogeneous ESP32-based embedded and IoT testbed with gateway-assisted post-quantum cryptographic processing. The proposed framework is validated through experimental implementations of the NIST-standardized ML-KEM key encapsulation mechanism and the ML-DSA digital signature algorithm under multiple communication protocols and heterogeneous hardware configurations. Experimental results demonstrate that QERS effectively distinguishes the trade-offs between security, computational efficiency, resource utilization, and communication performance, providing a practical decision-support framework for selecting appropriate PQC implementations. The proposed framework contributes a reproducible and extensible methodology for the system-level evaluation of post-quantum cryptography and establishes a foundation for future research into standardized resilience and trust assessment of quantum-resistant systems.