Fundamental And Practical Problems of QKD Security - the Actual and the Perceived Situation

TL;DR

This paper challenges the common belief that quantum key distribution (QKD) is unconditionally secure, highlighting fundamental and practical security issues in current models and experimental schemes.

Contribution

It critically examines the assumptions and limitations of existing security proofs for QKD, revealing gaps between theoretical security and real-world applicability.

Findings

Current QKD security claims are overly optimistic.

Fundamental security gaps exist in practical QKD implementations.

Security models need refinement to reflect real-world conditions.

Abstract

It is widely believed that quantum key distribution (QKD) has been proved unconditionally secure for realistic models applicable to various current experimental schemes. Here we summarize briefly why this is not the case, from both the viewpoints of fundamental quantitative security and applicable models of security analysis, with some morals drawn.