2025/04/29 by Akihiro Mizutani, Mizutani, Akihiro, Toshihiko Sasaki +3 · 3 citations
Computer Science · Engineering · Physics and Astronomy · #FOS: Physical sciences #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #Wireless Communication Security Techniques
paper · pdf · doi:10.48550/arxiv.2504.20417
openalex publication_date 2025/04/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper, we present a flowchart-based description of the decoy-state BB84 quantum key distribution (QKD) protocol and provide a step-by-step, self-contained information-theoretic security proof for this protocol within the universal composable security framework. As a result, our proof yields a key rate consistent with previous findings. Importantly, unlike all the prior security proofs, our approach offers a fully rigorous and mathematical justification for achieving the key rate with the claimed correctness and secrecy parameters, thereby representing a significant step toward the formal certification of QKD systems.