Barbosa<i>et al.</i>Reply:

Abstract

Yuan and Shields claim that our data-encryption protocol is entirely\nequivalent to a classical stream cipher utilizing no quantum phenomena. Their\nclaim is, indeed, false. Yuan and Shields also claim that schemes similar to\nthe one presented in Phys. Rev. Lett. 90, 227901 are not suitable for key\ngeneration. This claim is also refuted. In any event, we welcome the\nopportunity to clarify the situation for a wider audience.\n