The rapid digital transformation of academic record and student attendance systems demands security mechanisms that simultaneously provide confidentiality, integrity, privacy-preserving data analytics, and long-term resilience against emerging quantum threats. While conventional cryptographic algorithms such as RSA, ECC, and AES remain computationally efficient, public-key schemes based on RSA and ECC are vulnerable to quantum attacks, limiting their suitability for protecting sensitive educational information in the long term. Existing studies generally focus either on post-quantum secure communication or on privacy-preserving computation, resulting in fragmented security architectures that increase implementation complexity in resource-constrained academic environments. To address this challenge, this paper proposes a Lightweight Hybrid Post-Quantum Cryptographic Algorithm (LHPQCA) that integrates the CRYSTALS-Kyber Key Encapsulation Mechanism (KEM) for quantum-resistant session key establishment, AES-GCM for authenticated encryption of attendance records, and the Paillier additive homomorphic cryptosystem for privacy-preserving aggregation of attendance statistics over encrypted data. By assigning each cryptographic primitive according to its intended function, the proposed architecture achieves quantum-secure key establishment, efficient symmetric data protection, and secure encrypted computation without relying on post-quantum algorithms for bulk data encryption. Experimental evaluation demonstrates that incorporating the Paillier cryptosystem introduces only modest computational overhead while preserving practical encryption latency, reducing key establishment latency by 28–35%, decreasing CPU utilization by 22%, and maintaining bandwidth overhead below 12% compared with conventional hybrid deployment architectures that perform secure communication without privacy-preserving aggregation. These results demonstrate that the proposed integration of CRYSTALS-Kyber, AES-GCM, and the Paillier cryptosystem provides an effective balance between quantum resilience, computational efficiency, and privacy-preserving analytics, making LHPQCA suitable for next-generation academic attendance systems and other resource-constrained educational applications. Keywords - Post-Quantum Cryptography, Hybrid Cryptographic Algorithm, CRYSTALS-Kyber, Key Encapsulation Mechanism (KEM), AES-GCM, Paillier Cryptosystem, Privacy-Preserving Analytics.
The rapid digital transformation of academic record and student attendance systems demands security mechanisms that simultaneously provide confidentiality, integrity, privacy-preserving data analytics, and long-term resilience against emerging quantum threats. While conventional cryptographic algorithms such as RSA, ECC, and AES remain computationally efficient, public-key schemes based on RSA and ECC are vulnerable to quantum attacks, limiting their suitability for protecting sensitive educational information in the long term. Existing studies generally focus either on post-quantum secure communication or on privacy-preserving computation, resulting in fragmented security architectures that increase implementation complexity in resource-constrained academic environments. To address this challenge, this paper proposes a Lightweight Hybrid Post-Quantum Cryptographic Algorithm (LHPQCA) that integrates the CRYSTALS-Kyber Key Encapsulation Mechanism (KEM) for quantum-resistant session key establishment, AES-GCM for authenticated encryption of attendance records, and the Paillier additive homomorphic cryptosystem for privacy-preserving aggregation of attendance statistics over encrypted data. By assigning each cryptographic primitive according to its intended function, the proposed architecture achieves quantum-secure key establishment, efficient symmetric data protection, and secure encrypted computation without relying on post-quantum algorithms for bulk data encryption. Experimental evaluation demonstrates that incorporating the Paillier cryptosystem introduces only modest computational overhead while preserving practical encryption latency, reducing key establishment latency by 28–35%, decreasing CPU utilization by 22%, and maintaining bandwidth overhead below 12% compared with conventional hybrid deployment architectures that perform secure communication without privacy-preserving aggregation. These results demonstrate that the proposed integration of CRYSTALS-Kyber, AES-GCM, and the Paillier cryptosystem provides an effective balance between quantum resilience, computational efficiency, and privacy-preserving analytics, making LHPQCA suitable for next-generation academic attendance systems and other resource-constrained educational applications. Keywords - Post-Quantum Cryptography, Hybrid Cryptographic Algorithm, CRYSTALS-Kyber, Key Encapsulation Mechanism (KEM), AES-GCM, Paillier Cryptosystem, Privacy-Preserving Analytics.
The emergence of quantum computing poses a fundamental threat to current public key cryptographic systems. This threat is necessitating a transition to quantum resistant cryptographic alternatives in all the applications. In this work, we present the implementation of a practical hybrid end-to-end encryption system that combines classical and post-quantum cryptographic primitives to achieve both security and efficiency. Our system employs CRYSTALS-Kyber, a NIST-standardized lattice-based key encapsulation mechanism, for quantum-safe key exchange, coupled with AES-256-GCM for efficient authenticated symmetric encryption and SHA-256 for deterministic key derivation. The architecture follows a zero-trust model where a relay server facilitates communication without accessing plaintext messages or cryptographic keys. All encryption and decryption operations occur exclusively at client endpoints. The system demonstrates that NIST standardized post-quantum cryptography can be effectively integrated into practical messaging systems with acceptable performance characteristics, offering protection against both classical and quantum adversaries. As our focus is on implementation rather than on novelty, we also provide an open-source implementation to facilitate reproducibility and further research in post quantum secure communication 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.
My research focuses on developing a post-quantum cryptography (PQC) framework for securing institutional email systems against future quantum computing threats, particularly the Harvest-Now, Decrypt-Later (HNDL) attack. The study addresses a critical cybersecurity challenge faced by governments, healthcare institutions, universities, and organizations that rely on long-term confidentiality of sensitive communications.The proposed framework integrates the NIST-standardized ML-KEM-768 (formerly CRYSTALS-Kyber) for key encapsulation and ML-DSA-65 (formerly CRYSTALS-Dilithium) for digital signatures to provide quantum-resistant encryption and authentication. A hybrid cryptographic architecture combines PQC with AES-256-GCM to secure email content while maintaining compatibility with existing communication systems.A prototype was implemented using the Open Quantum Safe (liboqs v0.15.0) library and evaluated on resource-constrained hardware representative of institutions in developing countries (3-core Intel Core i5 processor and 4 GB RAM). Performance was measured over 100 benchmark iterations, comparing PQC algorithms with traditional RSA-2048 and ECDSA. The results showed that ML-KEM-768 achieved significantly faster key generation than RSA-2048 while maintaining low computational overhead, requiring less than 2% CPU utilization, under 8 MB of memory, and an end-to-end email processing latency of only 11–16 ms.The research introduces a formally specified HNDL threat model, evaluates the security implications of quantum-resistant cryptography in constrained environments, and discusses deployment considerations including certificate management, side-channel resistance, hybrid migration strategies, and institutional adoption. The work also identifies current limitations, such as the absence of forward secrecy and live production deployment, and proposes future enhancements including PQC-based key ratcheting, TLS integration, and real-world pilot deployments.This research contributes an end-to-end, standards-aligned, open-source framework demonstrating that post-quantum email security is practical and computationally feasible for resource-constrained institutions, particularly in developing economies, providing a pathway toward secure communication infrastructures resilient to future quantum attacks.
Quantum computing poses a growing challenge to conventional public-key cryptographic systems, particularly those relying on integer factorization and discrete logarithm problems. Widely deployed schemes such as RSA and elliptic curve cryptography are expected to become vulnerable as large-scale quantum computing capabilities emerge. This concern has intensified the demand for communication frameworks capable of maintaining long-term confidentiality in the presence of both classical and quantum-enabled adversaries. This paper presents a Hybrid Quantum-Resilient Key Exchange Algorithm (HKEA) that combines classical cryptographic mechanisms with lattice-based post-quantum cryptographic techniques to establish secure session keys. The proposed framework employs a dual-layer key establishment process in which classical and post-quantum shared secrets are integrated to generate a strengthened hybrid session key. The design aims to preserve compatibility with existing communication infrastructures while improving resistance to future quantum attacks and mitigating risks associated with Harvest-Now-Decrypt-Later (HNDL) threats. A prototype implementation was developed using Python-based cryptographic and post-quantum security libraries. The framework was evaluated using key generation time, latency, throughput, computational overhead, and security strength as performance indicators. Comparative analysis against conventional cryptographic approaches indicates that the proposed HKEA provides enhanced quantum resilience with only a modest increase in computational cost. The proposed approach offers a practical pathway toward secure and scalable communication systems for next-generation quantum-era network environments.
The accelerating development of large-scale quantum computers poses an existential threat to the public-key cryptographic infrastructure that underpins modern digital communication. Algorithms such as RSA and Elliptic Curve Cryptography (ECC), which currently secure internet traffic, digital signatures, and data-at-rest, are vulnerable to Shor's algorithm running on a sufficiently powerful quantum processor. In response, the U.S. National Institute of Standards and Technology (NIST) finalized the first post-quantum cryptography (PQC) standards in August 2024—FIPS 203 (ML-KEM/Kyber), FIPS 204 (ML-DSA/Dilithium), and FIPS 205 (SLH-DSA/SPHINCS+)—marking the beginning of a global migration toward quantum-resistant cryptography. This paper presents a hybrid C++/Python secure storage and communication platform (source code available at https://github.com/Sujithb128989/Quantum-Safe-Backend) that implements NIST-selected PQC algorithms in a production-oriented architecture. The backend employs CRYSTALS-Dilithium5 for quantum-resistant transport authentication, Kyber for key encapsulation, and AES-256-GCM for symmetric encryption-at-rest, delivered through a dual-stack gRPC/HTTP architecture containerized with Docker. We describe the system's design rationale, detail the cryptographic pipeline from certificate generation to atomic key rotation, and discuss the engineering challenges of integrating post-quantum primitives into real-world software systems.
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.