Security of quantum key distribution from generalised entropy accumulation
Abstract
The goal of quantum key distribution (QKD) is to establish a secure key between two parties connected by an insecure quantum channel. To use a QKD protocol in practice, one has to prove that a finite size key is secure against general attacks: no matter the adversary’s attack, they cannot gain useful information about the key. A much simpler task is to prove security against collective attacks, where the adversary is assumed to behave identically and independently in each round. In this work, we provide a formal framework for general QKD protocols and show that for any protocol that can be expressed in this framework, security against general attacks reduces to security against collective attacks, which in turn reduces to a numerical computation. Our proof relies on a recently developed information-theoretic tool called generalised entropy accumulation and can handle generic prepare-and-measure protocols directly without switching to an entanglement-based version.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 29, 2023
- Source ID
- 10.1038/s41467-023-40920-8
Entities
People
- Renato Renner
- Tony Metger
Organizations
- Air Force Office of Scientific Research
- National Center of Competence in Research Quantum Science and Technology
- Swiss National Science Foundation