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Erratum to: “Quantum secure direct communication based on order rearrangement of single photons” [Phys. Lett. A 358 (2006) 256]
Physics Letters A 368 (2007) 504 www.elsevier.com/locate/pla
Erratum
Erratum to: “Quantum secure direct communication based on order rearrangement of single photons” [Phys. Lett. A 358 (2006) 256] Jian Wang ∗ , Quan Zhang, Chao-jing Tang School of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China Received 3 March 2007 Available online 12 March 2007
In Ref. [1], Li et al. analyzed the security of the secure direct communication protocol proposed by Zhu et al. [2] (hereafter called ZXFZ protocol). They pointed out that the ZXFZ protocol is vulnerable to the Trojan horse attack strategy and then presented an improvement to solve the security problem in the ZXFZ protocol. In our protocol, we also utilize the secret transmitting order of particles to ensure the security of the protocol. Therefore, the similar loophole exists in our protocol. The single photon detector is only sensitive to the photons with a special wavelength. In invisible photon eavesdropping attack, an eavesdropper, Eve, can choose a special wavelength which is close to the legitimate wavelength to produce the invisible photons and insert the invisible photons to P -sequence. When Bob performs unitary operations on the legal photons, he also performs his operations on the invisible photons. After Bob sends P -sequence to Alice, Eve captures the invisible photons. When Bob publishes the secret order of the photon sequence, Eve can obtain Bob’s secret message. The delay-photon Trojan horse attack is inserting a spy photon in a legal signal with a delay time which is shorter than the time window. In our protocol, Eve can insert each spy photon after each legal signal with a delay time which is shorter than the time windows of Bob’s optical devices. Bob will perform the same operation on the spy photon as that on the legal signal. When Bob returns the rearranged photon sequence to Alice,
DOI of original article: 10.1016/j.physleta.2006.05.035. * Corresponding author.
E-mail address: [email protected] (J. Wang). 0375-9601/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.physleta.2007.03.002
Eve sorts out the spy photons. After Bob publishes the secret order of the transmitting photon sequence, Eve can obtain Bob’s secret message without being detected. To defeat Eve’s invisible photon eavesdropping and delayphoton Trojan horse attack, a filter and a photon number splitter (PNS: 50/50) should be introduced in our protocol. Bob should insert a filter in front of his devices to filter out the photon signal with an illegal wavelength. He then chooses a sufficiently large subset from P -sequence. Bob splits each sampling signal with a PNS and measures the two signals after the PNS with a random measuring basis (σz -basis or σx -basis). If the multiphoton rate is unreasonably high, Bob will abort the protocol. Acknowledgements We would like to express our thanks to Dr. F.G. Deng for helpful discussions. This work is supported by the National Natural Science Foundation of China under Grant No. 60472032. References [1] X.H. Li, F.G. Deng, H.Y. Zhou, Phys. Rev. A 74 (2006) 054302. [2] A.D. Zhu, Y. Xia, Q.B. Fan, S. Zhang, Phys. Rev. A 73 (2006) 022338.
Erratum
Erratum to: “Quantum secure direct communication based on order rearrangement of single photons” [Phys. Lett. A 358 (2006) 256] Jian Wang ∗ , Quan Zhang, Chao-jing Tang School of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China Received 3 March 2007 Available online 12 March 2007
In Ref. [1], Li et al. analyzed the security of the secure direct communication protocol proposed by Zhu et al. [2] (hereafter called ZXFZ protocol). They pointed out that the ZXFZ protocol is vulnerable to the Trojan horse attack strategy and then presented an improvement to solve the security problem in the ZXFZ protocol. In our protocol, we also utilize the secret transmitting order of particles to ensure the security of the protocol. Therefore, the similar loophole exists in our protocol. The single photon detector is only sensitive to the photons with a special wavelength. In invisible photon eavesdropping attack, an eavesdropper, Eve, can choose a special wavelength which is close to the legitimate wavelength to produce the invisible photons and insert the invisible photons to P -sequence. When Bob performs unitary operations on the legal photons, he also performs his operations on the invisible photons. After Bob sends P -sequence to Alice, Eve captures the invisible photons. When Bob publishes the secret order of the photon sequence, Eve can obtain Bob’s secret message. The delay-photon Trojan horse attack is inserting a spy photon in a legal signal with a delay time which is shorter than the time window. In our protocol, Eve can insert each spy photon after each legal signal with a delay time which is shorter than the time windows of Bob’s optical devices. Bob will perform the same operation on the spy photon as that on the legal signal. When Bob returns the rearranged photon sequence to Alice,
DOI of original article: 10.1016/j.physleta.2006.05.035. * Corresponding author.
E-mail address: [email protected] (J. Wang). 0375-9601/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.physleta.2007.03.002
Eve sorts out the spy photons. After Bob publishes the secret order of the transmitting photon sequence, Eve can obtain Bob’s secret message without being detected. To defeat Eve’s invisible photon eavesdropping and delayphoton Trojan horse attack, a filter and a photon number splitter (PNS: 50/50) should be introduced in our protocol. Bob should insert a filter in front of his devices to filter out the photon signal with an illegal wavelength. He then chooses a sufficiently large subset from P -sequence. Bob splits each sampling signal with a PNS and measures the two signals after the PNS with a random measuring basis (σz -basis or σx -basis). If the multiphoton rate is unreasonably high, Bob will abort the protocol. Acknowledgements We would like to express our thanks to Dr. F.G. Deng for helpful discussions. This work is supported by the National Natural Science Foundation of China under Grant No. 60472032. References [1] X.H. Li, F.G. Deng, H.Y. Zhou, Phys. Rev. A 74 (2006) 054302. [2] A.D. Zhu, Y. Xia, Q.B. Fan, S. Zhang, Phys. Rev. A 73 (2006) 022338.