Abstract Ensuring the long-term security and accessibility of digital resources is a critical challenge for libraries and archives. Traditional cryptographic methods, including RSA and elliptic curve schemes, are threatened by advances in quantum computing, which could compromise the confidentiality and authenticity of stored data. To address this, we present a Post-Quantum Digital Preservation and Secure File Sharing Framework that safeguards archival materials while enabling controlled user access. The framework integrates three core components: (i) a key encapsulation mechanism (KEM) for secure session key distribution; (ii) AES-GCM for efficient and file encryption; and (iii) digital signatures for authenticity verification. A dual-application design supports both repository operators and end-users: Repository operators encrypt, sign, and package digital assets into bundles, while users verify signatures, decrypt files, and restore content through a dedicated receiver GUI. Although the prototype employs X25519 and Ed25519 as placeholders, its architecture is fully compatible with NIST-standardized post-quantum algorithms such as Kyber (KEM) and Dilithium (signatures). By combining preservation with secure file sharing, the framework ensures confidentiality, authenticity, integrity, and resistance to quantum-era threats, offering a practical and forward-looking solution for Digital repositories.
Abstract Ensuring the long-term security and accessibility of digital resources is a critical challenge for libraries and archives. Traditional cryptographic methods, including RSA and elliptic curve schemes, are threatened by advances in quantum computing, which could compromise the confidentiality and authenticity of stored data. To address this, we present a Post-Quantum Digital Preservation and Secure File Sharing Framework that safeguards archival materials while enabling controlled user access. The framework integrates three core components: (i) a key encapsulation mechanism (KEM) for secure session key distribution; (ii) AES-GCM for efficient and file encryption; and (iii) digital signatures for authenticity verification. A dual-application design supports both repository operators and end-users: Repository operators encrypt, sign, and package digital assets into bundles, while users verify signatures, decrypt files, and restore content through a dedicated receiver GUI. Although the prototype employs X25519 and Ed25519 as placeholders, its architecture is fully compatible with NIST-standardized post-quantum algorithms such as Kyber (KEM) and Dilithium (signatures). By combining preservation with secure file sharing, the framework ensures confidentiality, authenticity, integrity, and resistance to quantum-era threats, offering a practical and forward-looking solution for Digital repositories.
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 arrival of cryptographically relevant quantum computers threatens the public-key primitives (RSA, Diffie-Hellman, and elliptic-curve cryptography) that secure essentially all current file-transfer and key-exchange systems, including through harvest-now-decrypt-later attacks. This paper presents QuantumVault, a working web-based file-sharing platform whose entire key-establishment and authentication path is built on the post-quantum algorithms standardized by NIST: ML-KEM (FIPS 203) for key encapsulation and ML-DSA (FIPS 204) for digital signatures, with AES-256-GCM for authenticated bulk encryption and a SHA-256 hash chain for tamper-evident auditing. We describe a hybrid sign-then-encrypt design in which each file is encrypted once under a random data-encryption key that is independently re-wrapped for every recipient using that recipient's post-quantum public key, enabling true multi-recipient sharing and constant-time revocation without re-encrypting file data. We report on the system architecture, the cryptographic workflow, an automated suite of 73 unit and end-to-end tests, an in-application cryptographic self-test, and the security properties the implementation enforces. We also state the system's boundaries candidly: encryption is performed server-side, and we outline a concrete path toward client-side end-to-end encryption as future work.
The advent of cryptographically relevant quantum computers poses an existential threat to current public-key cryptographic systems (RSA, ECC) widely used in digital communication protocols such as TLS, IPsec, VPNs, and secure messaging. Traditional systems face risks from "Harvest Now, Decrypt Later" attacks, compromising long-term confidentiality of sensitive data in finance, healthcare, government, and critical infrastructure. This paper proposes Quantum Shield, a comprehensive post-quantum secure framework for next-generation digital communication. It integrates NIST-standardized post-quantum algorithms (ML-KEM for key encapsulation, ML-DSA and SLH-DSA for digital signatures) with hybrid crypto-agile designs, hardware acceleration support, and role-based access controls. The system ensures quantum-resistant key establishment, authentication, and end-to-end encryption while maintaining low latency and high throughput. Experimental evaluation on simulated network traffic demonstrates acceptable performance overhead, enhanced resistance to quantum attacks, improved traceability, and secure multi-party coordination. Quantum Shield bridges the gap between classical and quantum-safe infrastructures, fostering trust and compliance in an era of quantum threats.
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.
The growing reliance on digital communication has increased the importance of protecting transmitted information from tampering, forgery, and other security threats. At the same time, advances in quantum computing have raised concerns regarding the long-term security of traditional cryptographic mechanisms used for authentication and integrity verification. To address these challenges, this paper proposes a quantum-resilient data integrity verification framework that combines AES-GCM, SHA-256, Elliptic Curve Verifiable Random Functions (ECVRF), and the post-quantum signature scheme ML-DSA. In the proposed framework, encrypted data are associated with a cryptographic digest, a publicly verifiable proof, and a post-quantum digital signature before transmission. A prototype implementation was developed and evaluated through security, computational, and communication-overhead analyses. Experimental results showed that the framework successfully detected ciphertext modification, signature forgery, and replay attacks while maintaining the integrity and authenticity of transmitted data. The evaluation also indicated that ECVRF contributes the largest share of computational cost, whereas ML-DSA is responsible for most of the communication overhead due to its signature size. The findings demonstrate that the proposed framework can provide a practical combination of integrity verification, authenticity assurance, and quantum-resistant security for data transmission over untrusted networks.
The rise of quantum computers threatens the security of current TLS protocols, which rely on elliptic curve and RSA-based primitives that quantum algorithms like Shor's can break. This creates a “store now, decrypt later” risk, where attackers may collect encrypted data today to decrypt it in the future once quantum capabilities advance. This study introduces a novel hybrid TLS protocol that seamlessly integrates classical (ECDSA and X25519) and post-quantum (CRYSTALS-Dilithium5 and CRYSTALS-Kyber1024) primitives. The proposed method generates a composite X. 509 certificate dual-signed with ECDSA and Dilithium5. It conducts a key exchange that concatenates an X25519 Diffie-Hellman shared secret with a Kyber KEM shared secret, followed by HKDF-SHA256 key derivation. The entire protocol is implemented in Go, leveraging the OQS liboqs-go library alongside Go's standard crypto packages. Experimental validation via a proof-of-concept demonstrates successful hybrid certificate validation and secure session establishment with both classical and post-quantum peers. These results confirm that hybrid cryptographic integration can provide quantum-resilient security while preserving compatibility with existing TLS deployments.