2017/05/30 by Christopher Portmann, Portmann, Christopher
Computer Science · Mathematics · Physics and Astronomy · #Cryptography and Security (cs.CR) #Entropy (arrow of time) #FOS: Computer and information sciences #FOS: Physical sciences #Information Theory (cs.IT) #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #Quantum mechanics #Statistical physics #cs.CR #cs.IT #math.IT #quant-ph
paper · pdf · doi:10.48550/arxiv.1705.10595
39+18 pages, 11 figures
arxiv created 2017/05/30 · openalex publication_date 2017/05/30 · arxiv updated 2017/05/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/08
We model (interactive) resources that provide Alice with a string X and a guarantee that any Eve interacting with her interface of the resource obtains a (quantum) system E such that the conditional (smooth) min-entropy of X given E is lower bounded by some k. This (abstract) resource specification encompasses any setting that results in the honest players holding such a string (or aborting). For example, it could be constructed from, e.g., noisy channels, quantum key distribution (QKD), or a violation of Bell inequalities, which all may be used to derive bounds on the min-entropy of X. As a first application, we use this min-entropy resource to modularize key distribution (KD) schemes by dividing them in two parts, which may be analyzed separately. In the first part, a KD protocol constructs a min-entropy resource given the (physical) resources available in the specific setting considered. In the second, it distills secret key from the min-entropy resource---i.e., it constructs a secret key resource. We prove security for a generic key distillation protocol that may use any min-entropy resource. Since the notion of resource construction is composable---security of a composed protocol follows from the security of its parts--- this reduces proving security of a KD protocol (e.g., QKD) to proving that it constructs a min-entropy resource. As a second application, we provide a composable security proof for the recent Fehr-Salvail protocol [EUROCRYPT 2017] that authenticates classical messages with a quantum message authentication code (Q-MAC), and recycles all the key upon successfully verifying the authenticity of the message. This protocol uses (and recycles) a non-uniform key, which we model as consuming and constructing a min-entropy resource.