Security of Y-00 and similar quantum cryptographic protocols

TL;DR

This paper refutes the claim that Y-00 quantum cryptographic protocols are equivalent in security to classical stream ciphers, demonstrating their security across all operational parameters and clarifying their security properties.

Contribution

It provides a comprehensive analysis showing that Y-00 protocols are not equivalent to classical ciphers, correcting previous misconceptions about their security.

Findings

Y-00 security is not equivalent to classical stream ciphers.

Y-00 remains secure across all tested parameters.

Clarifies the security properties of Y-00 protocols.

Abstract

It is claimed in Phys. Lett. A by T. Nishioka et. al. 327 (2004) 28-32, that the security of Y-00 is equivalent to that of a classical stream cipher. In this paper it is shown that the claim is false in either the use of Y-00 for direct encryption or key generation, in all the parameter ranges it is supposed to operate including those of the experiments reported thus far. The security of Y-00 type protocols is clarified.