The transition toward Post-Quantum Cryptography (PQC) necessitates robust frameworks to evaluate not only algorithmic complexity but also physical resilience against information leakage. This study introduces a novel benchmarking architecture that integrates Quantum Speed Limits (QSL) with the Kubo-Mori linear response theory to quantify the security of NIST-standardized PQC primitives, specifically Kyber-512 and Dilithium-2. We propose a “Hydrodynamic Defense” mechanism based on Susceptibility Locking, which utilizes structured dissipative noise—modeled through dephasing and amplitude-damping Lindbladian superoperators—to suppress the information copying capacity of potential adversaries. Our numerical simulations, conducted on a multi-qubit Hilbert space, demonstrate a significant reduction in the receiver’s second-order susceptibility (), effectively increasing the Information Copy Time () and providing a physical layer of provable security. The results reveal that controlled environmental coupling can be leveraged as a strategic countermeasure, transforming dissipative channels into protective barriers that safeguard cryptographic secrets against physical-layer exploitation. This work establishes a foundational bridge between quantum thermodynamics and cryptographic hardware security, offering a scalable pathway for the design of next-generation secure quantum-classical hybrid infrastructures.
The transition toward Post-Quantum Cryptography (PQC) necessitates robust frameworks to evaluate not only algorithmic complexity but also physical resilience against information leakage. This study introduces a novel benchmarking architecture that integrates Quantum Speed Limits (QSL) with the Kubo-Mori linear response theory to quantify the security of NIST-standardized PQC primitives, specifically Kyber-512 and Dilithium-2. We propose a “Hydrodynamic Defense” mechanism based on Susceptibility Locking, which utilizes structured dissipative noise—modeled through dephasing and amplitude-damping Lindbladian superoperators—to suppress the information copying capacity of potential adversaries. Our numerical simulations, conducted on a multi-qubit Hilbert space, demonstrate a significant reduction in the receiver’s second-order susceptibility (), effectively increasing the Information Copy Time () and providing a physical layer of provable security. The results reveal that controlled environmental coupling can be leveraged as a strategic countermeasure, transforming dissipative channels into protective barriers that safeguard cryptographic secrets against physical-layer exploitation. This work establishes a foundational bridge between quantum thermodynamics and cryptographic hardware security, offering a scalable pathway for the design of next-generation secure quantum-classical hybrid infrastructures.
The rapid advancement of quantum computing poses an existential threat to classical public-key cryptographic systems, necessitating the transition to post-quantum cryptography (PQC). However, the deployment of lattice-based PQC schemes such as CRYSTALS-Kyber and CRYSTALS-Dilithium faces significant challenges including computational complexity, noise sensitivity, resource constraints, and security vulnerabilities. This research presents a comprehensive hybrid quantum-classical optimization framework for efficient and noise-tolerant post-quantum cryptographic systems. The framework addresses three primary objectives: (1) developing a unified hybrid quantum-classical optimization architecture that integrates variational quantum algorithms (VQE, QAOA) and QUBO/Ising formulations with classical PQC primitives based on the Learning With Errors (LWE) and Module-LWE problems; (2) designing noise-tolerant PQC protocols through multi-layer noise modeling that characterizes cryptographic, quantum hardware, and classical implementation noise; and (3) enabling resource-aware deployment on constrained platforms including embedded systems, IoT devices, and edge computing nodes. Experimental evaluation demonstrates that the QUBO formulation achieves coefficient ranges suitable for NISQ devices with 99.2% of coefficients within [-1, 1] after normalization. The adaptive partitioning algorithm achieves time-to-solution improvements of 42% for large problem instances compared to classical-only execution. The noise-aware optimization framework achieves decryption failure rate improvements ranging from 2^10.8 to 2^16.8, with combined noise tolerance success rates exceeding 94.56% under severe conditions. Side-channel countermeasures achieve 82.6% reduction in exploitable information leakage, with power leakage correlation reduced from 0.23 to 0.04. The unified Kyber-Dilithium architecture achieves 21% memory savings and 10-11% performance improvements. Reinforcement learning-based scheduling reduces latency by 37% and energy consumption by 39% compared to static scheduling. End-to-end deployment evaluation across smart home, industrial IoT, healthcare, and autonomous vehicle scenarios demonstrates that the hybrid PQC system meets latency and energy requirements while maintaining target security levels. This research provides a practical pathway toward secure communication in the quantum era, bridging the gap between current classical systems and future quantum-enabled solutions.
Quantum computing is rapidly approaching a stage where classical cryptographic systems, particularly RSA, ECC, and Diffie–Hellman, will no longer provide adequate security for critical infrastructure. The emergence of Shor’s and Grover’s algorithms introduces unprecedented vulnerability to national cyber-defense ecosystems, underpinning power grids, transportation, military communications, and banking systems. This paper presents a unified post-quantum cryptographic (PQC) security framework integrating lattice-based primitives, hybrid key-exchange mechanisms, and secure orchestration for resource-constrained operational-technology environments. The proposed architecture leverages NIST-recommended schemes, including CRYSTALS-Kyber, CRYSTALS-Dilithium, and SPHINCS+, to ensure long-term confidentiality, integrity, and interoperability across legacy and modern control environments. A defense-in-depth trust-fabric is introduced to protect critical data flows across edge controllers, automation PLCs, substations, cloud-SCADA gateways, and defense communication systems. Performance evaluation demonstrates a 39.4% reduction in key-exchange latency, 46% faster authentication cycles, and zero-downtime cryptographic transition capability. Our findings position this framework as a practical migration blueprint supporting national PQC readiness and cyber-resilience mandates.
As the advent of quantum computing threatens traditional cryptographic protocols, hybrid classical-quantum secure communication infrastructures have emerged as a critical frontier in cybersecurity. This paper explores the integration of post-quantum cryptographic algorithms—specifically CRYSTALS-Kyber for key encapsulation and CRYSTALS-Dilithium for digital signatures—into hybrid communication architectures designed to resist quantum-level attacks. Leveraging lattice-based cryptographic primitives, both algorithms have been selected for standardization by NIST due to their robust security and performance characteristics. This study evaluates their implementation in real-world communication stacks, assesses latency and throughput under hybrid channel configurations, and proposes a layered security architecture combining classical and quantum-resilient mechanisms. Furthermore, it examines key management, digital trust, and infrastructure scalability in a post-quantum context. Simulation results and hardware-based validations are used to determine practical deployment feasibility in critical sectors such as finance, defense, and healthcare. The findings offer a comprehensive framework for securing data in transitional computing eras, ensuring forward secrecy, and maintaining operational integrity against future adversarial quantum threats.
The looming threat of large-scale quantum computers necessitates a paradigm shift in cryptographic design, giving rise to the field of Post-Quantum Cryptography (PQC). While the computational hardness assumptions underpinning PQC schemes are well-studied, their fundamental security limits from an information-theoretic perspective remain an area requiring deeper exploration. This paper introduces and systematically investigates the concept of "entropic resilience," defined as the inherent ability of a cryptographic system to maintain its security guarantees even under an adversary possessing unbounded computational power, provided only limited information about the secret components is revealed. We present a comprehensive framework for analyzing the information-theoretic security of prominent PQC families, including lattice-based, code-based, and hash-based schemes. Our methodology leverages various entropy measures, such as min-entropy and conditional entropy, to quantify the information leakage and the irreducible uncertainty preserved in cryptographic secrets. We derive theoretical bounds on the information-theoretic security for representative PQC constructions and discuss the implications of these bounds for parameter selection, key generation, and resistance against information-theoretic attacks and side channels. The findings highlight critical trade-offs between entropy requirements, efficiency, and the achievable level of provable security in a post-quantum world. Ultimately, this work provides a foundational understanding of the ultimate security boundaries for PQC, guiding the design of more robust and provably secure schemes against both classical and quantum adversaries.
The advent of quantum computing has precipitated an estimated attack resistant cryptography system necessitating quantum attacks. The classical asymmetric algorithms, i.e., RSA and ECC are susceptible to Shor algorithm and a transition should be made to Post-Quantum Cryptography (PQC) anymore. The novelty of this work lies in providing a unified comparative framework that analyzes PQC families through security assumptions, concrete key/ciphertext sizes, and implementation complexity an aspect not addressed collectively in prior surveys. This survey gives a general picture of the status of the design process and general evaluation of PQC accounting its application within the paradigm of the diversified networks including the IoT and 5G/6G and in the cyber-physical environment. Furthermore, this review uniquely synthesizes practical hybrid‑deployment strategies, including protocol layering, coexistence models, and backward‑compatibility mechanisms, offering actionable guidance for real‑world migration. Additionally, the manuscript contributes a prioritized list of open problems across IoT, 5G/6G, blockchain, and cyber‑physical systems, highlighting domains facing the most urgent quantum‑resilience challenges. In this paper, the authors will evaluate the most popular PQC schemes, including schemes based on lattice, code, hash, and isogeny, depending on their performance, scalability, and interoperability (with reference to the recent research). It also examines the problems of integration as implemented with respect to the computational overhead, latency and adoption of hybrid with classical cryptography. This is expounded more to the standardization of PQC by NISTs and with a focus on such algorithms as CRYSTALS-Kyber and Dilithium. The findings suggest that, hybrid PQC protocols are able to control quantum resistance and actual performance in numerous infrastructures in computing systems.
The advent of quantum computing poses a significant threat to classical cryptographic systems, necessitating the development of quantum-resistant alternatives. This thesis explores a hybrid key exchange framework combining Quantum Key Distribution (QKD) with Post-Quantum Cryptography (PQC) to secure classical post-processing steps such as information reconciliation and privacy amplification. Specifically, CRYSTALS-Kyber is used for key encapsulation, while CRYSTALS-Dilithium and SPHINCS+ provide digital signatures for authentication. While the mathematical security foundations of these algorithms are assumed, their integration is evaluated through performance benchmarking and system-level analysis. The results show that incorporating PQC-based authentication into QKD post-processing significantly improves resilience against quantum adversaries, while introducing only a reasonable computational and bandwidth overhead. This work contributes to the development of robust hybrid cryptographic systems capable of with standing both classical and quantum-era threats.