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Forcible-Measurement Attack on Quantum Secure Direct Communication Protocol with Cluster State 下载免费PDF全文
The security of the quantum secure direct communication (QSDC) protocol with cluster state is analysed. It is shown that the secret would be partially leaked out when an eavesdropper performs forcible measurements on the transmitted particles. With the help of the result in minimum error discrimination, an upper bound (i.e. 40%) of this leakage is obtained. Moreover, the particular measurements which makes the leakage reach this bound are given. 相似文献
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Cryptanalysis of Multiparty Quantum Secret Sharing of Quantum State Using Entangled States 下载免费PDF全文
Security of a quantum secret sharing of quantum state protocol proposed by Guo et al. [Chin. Phys. Lett. 25 (2008) 16] is reexamined. It is shown that an eavesdropper can obtain some of the transmitted secret information by monitoring the classical channel or the entire secret by intercepting the quantum states, and moreover, the eavesdropper can even maliciously replace the secret message with an arbitrary message without being detected. Finally, the deep reasons why an eavesdropper can attack this protocol are discussed and the modified protocol is presented to amend the security loopholes. 相似文献
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The quantum secure direct communication (QSDC) protocol with a random basis and order is analysed and an effective attack, i.e. teleportation attack, is presented. An eavesdropper can obtain half of the transmitted secret bits with the help of this special attack. It is shown that quantum teleportation can be employed to weaken the role of the order-rearrangement encryption at least in a certain circumstance. Meanwhile, a possible improvement on this protocol is proposed, which makes it secure against this kind of attack. 相似文献
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This paper proposes a scheme for teleporting a kind of essential three-particle
non-symmetric entangled state, which is much more valuable than a GHZ and W state
for some applications in quantum information processing. In comparison with previous
proposal of teleportation, the resources of entangled states as quantum channel and
the number of classical messages required by our scheme can be cut down. Moreover,
it is shown that there exists a class of transformations which ensure the success of
this scheme, because the two-particle transformation performed by the receiver in
the course of teleportation may be a generic two-particle operation instead of a
control-NOT (CNOT) operation. In addition, all kinds of transformations performed by
sender and receiver are given in detail. 相似文献
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In this paper an efficient quantum secure direct communication (QSDC) scheme with
authentication is presented, which is based on quantum entanglement and
polarized single photons. The present protocol uses Einstein--Podolsky--Rosen
(EPR) pairs and polarized
single photons in batches. A particle of the EPR pairs is retained
in the sender's station, and the other is transmitted forth and back
between the sender and the receiver, similar to the `ping--pong'
QSDC protocol. According to the shared information beforehand, these
two kinds of quantum states are mixed and then transmitted via a
quantum channel. The EPR pairs are used to transmit secret messages
and the polarized single photons used for authentication and
eavesdropping check. Consequently, because of the dual contributions
of the polarized single photons, no classical information is needed.
The intrinsic efficiency and total efficiency are both 1 in this
scheme as almost all of the instances are useful and each EPR pair
can be used to carry two bits of information. 相似文献
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Utilizing the generalized measurement described by positive operator-wlued measure, this paper comes up with a protocol for teleportation of an unknown multi-particle entangled (GHZ) state with a certain probability. The feature of the present protocol is to weaken requirement for the quantum channel initially shared by sender and receiver. All unitary transformations performed by receiver are summarized into a formula. On the other hand, this paper explicitly constructs the efficient quantum circuits for implementing the proposed teleportation by means of universal quantum logic operations in quantum computation. 相似文献
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The security of the multiparty quantum secret sharing protocol proposed by Gao [G. Gao, Commun. Theor. Phys. 52 (2009) 421] is analyzed. It is shown that this protocol is vulnerable since the agents' imperfect encryption scheme can be attacked by a powerful participant. We introduce a attack strategy called participant forcible manipulation and analyze the information leakage in this protocol under this attack. At last, we give an improved version of the original protocol. The improved protocol is robust and has the same efficiency as the original one. 相似文献