P. G. Kwiat, Phys. Rev. Lett. [**84,**]{} 4733 (2000); M. Genovese, Phys. Rev. A [**63,**]{} 044303 (2001); M. Williamson and V. Vedral, J. Mod. Opt. [**50,**]{} 1989 (2003). H. E. Brandt, Phys. Rev. A [**71,**]{} 042312 (2005). C. H. Bennett, T. Mor, and J. A. Smolin, Phys. Rev. A [**54,**]{} 2675 (1996); E. Biham and T. Mor, Phys. Rev. Lett. [**78,**]{} 2256 (1997); E. Biham, M. Boyer, G. Brassard, J. van de Graaf, and T. Mor, Algorithmica [**34,**]{} 372 (2002). C. A. Fuchs and A. Peres, Phys. Rev. A [**53,**]{} 2038 (1996). B. A Slutsky, R. Rao, P,-C. Sun, and Y. Fainman, Phys. Rev. A [**57,**]{} 2383 (1998). Equation (\[probeinput\]) corrects an error in [@FPB]. Because of an extraneous root problem, the expression for Eve’s target-qubit input state in that paper is only correct for $0\le P_E\le 1/4$. This can be seen by comparing the input probe state $|A_2\rangle$ from Eq. (207) of [@FPB] with our target-qubit input state $|T_{\rm in}\rangle$ from Eq. (\[probeinput\]). The former coincides with the latter for $0\le P_E\le 1/4$, but not for $1/4 < P_E \le 1/2$. Indeed, because Brandt’s $|A_2\rangle$ states for $P_E = 1/4 \pm x$ are identical, for all $0\le x\le 1/4$, 