Cloud computing systems face serious security risks that are intensified by advances in quantum computing because powerful quantum algorithms such as Shor's algorithm can break widely used public-key schemes which include RSA and ECC. The cloud environment needs Post-Quantum Cryptography (PQC) and Quantum Key Distribution (QKD) as countermeasures but their individual deployment creates problems because scalability and infrastructure requirements become obstacles for multi-tenant systems. This research proposes a hybrid security architecture that uses both hardware-based QKD for symmetric key generation over optical fibers and PQC for authentication through quantum-resistant key encapsulation using CRYSTALS-Kyber and digital signatures with CRYSTALS-Dilithium. The hybrid design uses XOR to combine the QKD-generated secret with the PQC-derived key material which creates the final session key yet security remains intact if either component gets compromised. The system tested on a private cloud testbed with 10 virtual machines and a 50 km commercial QKD link through optical fiber measured performance against Classical TLS 1.3 and PQC-TLS and QKD-only configurations. The results showed that QKD-only achieved the lowest handshake latency of 5.2 ms while the hybrid approach delivered the strongest security through a 19.8 ms overhead which was only 1.7 ms slower than pure PQC. After creating the secure channel all systems achieved similar data throughput of about 942 Mbps which shows that quantum-security mechanisms affect the connection setup phase instead of persistent data transfer.
Cloud computing systems face serious security risks that are intensified by advances in quantum computing because powerful quantum algorithms such as Shor's algorithm can break widely used public-key schemes which include RSA and ECC. The cloud environment needs Post-Quantum Cryptography (PQC) and Quantum Key Distribution (QKD) as countermeasures but their individual deployment creates problems because scalability and infrastructure requirements become obstacles for multi-tenant systems. This research proposes a hybrid security architecture that uses both hardware-based QKD for symmetric key generation over optical fibers and PQC for authentication through quantum-resistant key encapsulation using CRYSTALS-Kyber and digital signatures with CRYSTALS-Dilithium. The hybrid design uses XOR to combine the QKD-generated secret with the PQC-derived key material which creates the final session key yet security remains intact if either component gets compromised. The system tested on a private cloud testbed with 10 virtual machines and a 50 km commercial QKD link through optical fiber measured performance against Classical TLS 1.3 and PQC-TLS and QKD-only configurations. The results showed that QKD-only achieved the lowest handshake latency of 5.2 ms while the hybrid approach delivered the strongest security through a 19.8 ms overhead which was only 1.7 ms slower than pure PQC. After creating the secure channel all systems achieved similar data throughput of about 942 Mbps which shows that quantum-security mechanisms affect the connection setup phase instead of persistent data transfer.
The evolving potential disaster of quantum computing against the classical cryptographic methods requires the invention of immune post-quantum cryptographic (PQC) systems to cloud based key management system (CKMS). The proposed solution throughout this paper is considering the risk of existing public-key infrastructures when used in a cloud computing setup by incorporating lattice based post-quantum techniques i.e CRYSTALS-Kyber and CRYSTALS-Dilithium into cloud key management system structures. We came up with a prototype and simulated a hybrid CKMS structure encompassing classical and PQC protocols to secure backward contact and forward confidentiality. Benchmarking provides evidence that the PQC-enhanced CKMS registers 98.7 percent decrease of vulnerability to quantum attack vectors; its key generation time credit stays at 1.24 ms, and time to distribute keys at 5.6 ms, which is equivalent to RSA-2048 based systems. Comparative analysis provided an increase in computational efficiency by 34 percent and a decrease of bandwidth overhead by 22 percent using batch key encapsulation optimization. We have found that the given architecture does not only maintain the scalability of cloud environments but also implements long-term cryptographic resilience. The results show the feasibility and the strength of PQC on the integration into the existing cloud key management infrastructures.
The Hybrid approach in Quantum Cryptography creates adaptable security model which provides the safest Communication in the emerging quantum era. The development of quantum computing raise questions about the long-term security. Traditional algorithms, such as RSA, ECC, and Diffie-Hellman, which is seemed computationally secure but it can be effectively solved by quantum algorithms such as Shor's and Grover's. This problem leads to the origination of two key trends in current studies, namely Post-Quantum Cryptography (PQC), designing mathematical approaches to encryption resistant to quantum attacks; Quantum Key Distribution (QKD) using the principles of quantum mechanics to assure security in communications. Accordingly, this research proposes a hybrid security framework including reliable data encryption and authentication using PQC, combined with the safe key- exchange method of QKD. The model is implemented in Python, Qiskit, and PQClean's Kyber and Dilithium algorithms to show how these two paradigms can cooperate toward quantum- resilient communication. To present the system performance, key exchange efficiency, computational overhead, and security strength have been considered. According to the results, this hybrid approach gives superior defense against quantum threats while maintaining practical effectiveness for real-world applications such as cloud security, 6G networks, and the Internet of Things.
The speedy evolution of cyber threats is a serious threat to the protection of sensitive health information, with increasing threats from quantum computing. Conventional security does not keep up with evolving threats, and innovative solutions are needed. This paper introduces a secure hybrid cloud architecture that combines post-quantum cryptography (PQC), advanced hashing, and quantum key distribution (QKD) to authenticate further and protect data in healthcare systems. The primary mission is to generate an attack-resistant authentication process, robust data integrity assurance, and a functional system for key management with extensibility and regulation compliance. The considered infrastructure utilizes PQC-based robust encryption, robust hashing to authenticate data integrity, and QKD for providing secure key exchange augmented with multi-factor authentication. Implementing quantum-resistant protocols properly secures healthcare data in public and private cloud centers. Performance testing reveals a 99.6% overall success rate, 99.8% key exchange success, and 99.9% detection accuracy with QKD. PQC integration offers robust encryption, and advanced hashing techniques offer tamper-evident data integrity. The results establish the strong security, scalability, and quantum age cyber threat tolerance of the approach as a secure solution for guarding healthcare applications and delivering confidential, integrity-guaranteeing data protection.
The rapid advancement of quantum computing introduces unprecedented security threats to modern cloud and edge computing infrastructures. Classical public-key cryptographic algorithms such as RSA, Diffie–Hellman, and Elliptic Curve Cryptography (ECC) are fundamentally vulnerable to quantum attacks enabled by Shor’s algorithm. As a result, the confidentiality, integrity, and authenticity of data stored and processed in distributed systems are at serious risk.Post-quantum cryptography (PQC) aims to develop cryptographic algorithms that are resistant to both classical and quantum adversaries. This paper presents a comprehensive quantum-resilient cryptographic framework designed specifically for post-quantum cloud and edge computing environments. The framework integrates post-quantum cryptographic primitives, hybrid cryptographic approaches, crypto-agile architectures, and secure key management mechanisms. The proposed framework addresses performance constraints, scalability requirements, and deployment challenges in heterogeneous environments. A detailed discussion of security threats, architectural components, performance considerations, and future research directions is provided. The proposed approach enables longterm security and supports a smooth transition toward quantum-safe distributed computing systems.
The fast development of cyber communications, multimedia distribution, remote working have promoted the demand to transmit sensitive information through secure means in both the public and the private networks. The advent of massive quantum computers is rendering traditional cryptographic algorithms like RSA and Elliptic Curve Cryptography (ECC) insecure because they can crack the classical public-key algorithms like the Shor and Grover algorithms. This brings an immediate need of hybrid cryptographic systems, which integrate classical, quantum, and post-quantum algorithms to provide confidentiality, integrity, authentication, and future security beyond the quantum threat horizon.The paper is a proposal of a Hybrid Quantum-Post-Quantum Cryptographic Framework of transmitting files safely. It starts by aggregating files, which is a process to compress several files, images, videos, and multimedia files that users have chosen into one file to minimize redundancy and ease encryption. The AES-256 encrypted file is in GCM mode and provides confidentiality and integrity of the compressed file.The dual-layer mechanism ensures key establishment security. To begin with, Quantum Key Distribution (QKD) based on the protocols of BB84/E91 allows the Sender and the Receiver to generate a Quantum Secret Key (QSK) by exchanging quantum bits in quantum channel. Constant monitoring of the error rate facilitates automatic eavesdropping detection, and guarantees the keys generation is made when the conditions are secure, as well as the safeguarding of interception and man-in-the-middle attacks.A post-quantum layer is provided to ensure long-term security against quantum cryptanalysis, which uses Kyber, a NIST-approved lattice-based Key Encapsulation Mechanism (KEM). The Receiver creates a key pair of Kyber and disseminates the public key to the Sender. By using encapsulation, the Sender gets a PQC ciphertext and a Shared Secret (SS), with decapsulation on the Receiver side giving ensure that only participants of good faith get the same secret value.The hybridization phase consists of combining the QSK of QKD and SS of Kyber with the help of HKDF-SHA256 to obtain a Final Wrap Key (FWK). AES-GCM encrypts the key of file encryption by wrapping it with FWK which allows a secure and authenticated transfer of the key. The Sender sends four messages: encrypted file, Kyber ciphertext, wrapped AES key and the initialisation vector. At Receiver end, FWK is calculated once again with the help of QSK and SS so that the original data can be decrypted with the help of AES key.The suggested framework provides a defense-in-depth solution based on the combination of quantum security, post-quantum resilience and authenticated symmetric encryption. It can be analyzed that there is a strong resistance to classical and quantum adversaries, scalability, and compatibility with the existing communication networks. This renders the model to be appropriate to secure government communication, military systems, data exchange in healthcare environments, cloud storage and financial infrastructures. Keywords— Quantum Key Distribution (QKD), Post-Quantum Cryptography (PQC), Kyber,Key Encapsulation Mechanism (KEM), HKDF-SHA256, Quantum Secret Key (QSK), GCM Mode.
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.