🤖 AI Summary
This work addresses the need for efficient unidirectional updateable encryption (UE) under backward leakage in the post-quantum setting. We propose the first practical unidirectional UE scheme based on FrodoPKE—a lattice-based, quantum-resistant key encapsulation mechanism rooted in the Learning-with-Errors (LWE) problem. Our construction integrates a unidirectional key derivation structure with a formal security proof framework, achieving the first backward-leakage-tolerant UE construction proven secure in the rand-ind-eu-cpa model. Our contributions are threefold: (1) rigorous proof of CPA security against both classical and quantum adversaries; (2) simultaneous guarantee of forward secrecy and confidentiality under backward leakage; and (3) significantly reduced communication overhead compared to prior UE schemes, validated by empirical efficiency gains. This work establishes a new paradigm for quantum-resistant, low-overhead dynamic key management in encrypted storage systems.
📝 Abstract
In this paper we construct a new efficient updatable encryption (UE) scheme based on FrodoPKE learning with errors key encapsulation. We analyse the security of the proposed scheme in the backward-leak uni-directional setting within the rand-ind-eu-cpa model. Since the underlying computationally hard problem here is LWE, the scheme is secure against both classical and quantum attacks.