Related papers: Correct mutual information, quantum bit error rate…
In this paper the correct calculations of the mutual information of the whole transmission, the quantum bit error rate (QBER) are presented. Mistakes of the general conclusions relative to the mutual information, the quantum bit error rate…
The proposed eavesdropping scheme reveals that the quantum communication protocol recently presented by Bostrom and Felbinger [Phys. Rev. Lett. 89, 187902 (2002)] is not secure as far as quantum channel losses are taken into account.
The eavesdropping scheme proposed by W\'{o}jcik [Phys. Rev. Lett. {\bf 90},157901(2003)] on the ping-pong protocol [Phys. Rev. Lett. {\bf 89}, 187902(2002)] is improved by constituting a new set of attack operations. The improved scheme has…
We show an eavesdropping scheme on Bostr\UNICODE{0xf6}m-Felbinger communication protocol (called ping-pong protocol) [Phys. Rev. Lett. 89, 187902 (2002)] in an ideal quantum channel. A measurement attack can be perfectly used to eavesdrop…
The existence of an undetectable eavesdropping of dense coded information has been already demonstrated by Pavi\v{c}i\'c for the quantum direct communication based on the ping-pong paradigm. However, a) the explicit scheme of the circuit is…
We introduce an attack scheme for eavesdropping the ping-pong quantum communication protocol proposed by Bostr$\ddot{o}$m and Felbinger [Phys. Rev. Lett. \textbf{89}, 187902 (2002)] freely in a noise channel. The vicious eavesdropper, Eve,…
The crucial issue of quantum communication protocol is its security. In this paper, we show that all the deterministic and direct two-way quantum communication protocols, sometimes called ping-pong (PP) protocols, are insecure when an…
We present a quantum communication protocol which keeps all the properties of the ping-pong protocol [Phys. Rev. Lett. 89, 187902 (2002)] but improves the capacity doubly as the ping-pong protocol. Alice and Bob can use the variable…
The general individual (non-coherent) attack on the ping-pong protocol with completely entangled pairs of three-dimensional quantum systems (qutrits) is analyzed. The expression for amount of the eavesdropper's information as functions from…
In this Reply we propose a modified security proof of the Quantum Dense Key Distribution protocol detecting also the eavesdropping attack proposed by Wojcik in his Comment.
Employing the fundamental laws of quantum physics, Quantum Key Distribution (QKD) promises the unconditionally secure distribution of cryptographic keys. However, in practical realisations, a QKD protocol is only secure, when the quantum…
The safety of a quantum key distribution system relies on the fact that any eavesdropping attempt on the quantum channel creates errors in the transmission. For a given error rate, the amount of information that may have leaked to the…
We briefly review the security of the ping-pong protocol in light of several attack scenarios suggested by various authors since the proposal of the protocol. We refute one recent attack on an ideal quantum channel, and show that a recent…
Security of quantum key distribution (QKD) protocols relies solely on quantum physics laws, namely, on the impossibility to distinguish between non-orthogonal quantum states with absolute certainty. Due to this, a potential eavesdropper…
Communication security with quantum key distribution has been one of the important features of quantum information theory. A novel concept of secured direct communication has been the next step forward without the need to establish any…
The eavesdropping scheme proposed by W\'{o}jcik [Phys. Rev. Lett. {\bf 90},157901(2003)] on the quantum communication protocol of Bostr\"{o}m and Felbinger [Phys. Rev. Lett. {\bf 89}, 187902(2002)] is improved by constituting a new set of…
We present security proofs for a protocol for Quantum Key Distribution (QKD) based on encoding in finite high-dimensional Hilbert spaces. This protocol is an extension of Bennett's and Brassard's basic protocol from two bases, two state…
Two protocols of quantum direct communication with authentication [Phys. Rev. A {\bf 73}, 042305 (2006)] are recently proposed by Lee, Lim and Yang. In this paper we will show that in the two protocols the authenticator Trent should be…
We devise a simple modification that essentially doubles the efficiency of a well-known quantum key distribution scheme proposed by Bennett and Brassard (BB84). Our scheme assigns significantly different probabilities for the different…
Two-way quantum key distribution protocols utilize bi-directional quantum communication to establish a shared secret key. Due to the increased attack surface, security analyses remain challenging. Here we investigate a high-dimensional…