A Post-Quantum Digital Preservation and Secure File Sharing Framework for Library 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.