Key Generation: Foundations and a New Quantum Approach

TL;DR

This paper introduces a new quantum key generation approach called KCQ, analyzing its security, efficiency, and potential for practical implementation compared to existing protocols like BB84.

Contribution

It develops the KCQ quantum cryptography method based on quantum detection theory, offering a novel approach with practical finite-length protocols.

Findings

KCQ schemes can generate fresh keys with coherent states under heterodyne attacks

Security analysis based on attacker’s optimal probability of key discovery

Comparison shows KCQ's advantages over BB84 in certain scenarios

Abstract

The fundamental security and efficiency considerations for fresh key generation will be described. It is shown that the attacker's optimal probability of finding the generated key is an indispensable measure of security and that this probability limits the possibility of privacy amplification and the amount of fresh key that can be generated. A new approach to quantum cryptography to be called KCQ, keyed communication in quantum noise, is developed on the basis of quantum detection and communication theory for classical information transmission. KCQ key generation schemes with coherent states of considerable energy will be described. The possibility of fresh key generation is demonstrated for binary and N-ary detection systems under heterodyne attacks. The security issues of these schemes will be discussed and compared with BB84. The emphasis throughout is on concrete finite bit-length protocols.