共查询到20条相似文献,搜索用时 15 毫秒
1.
Based on the controlled order rearrange encryption (CORE) for quantum key distribution using EPR pairs [Fu.G. Deng, G.L. Long, Phys. Rev. A 68 (2003) 042315], we propose a generalized controlled order rearrangement encryption (GCORE) protocol using non-maximally entangled W-class states with probability, but it also has full efficiency and we compare the similarity and difference with original protocol. Besides, we use this W-class state to split quantum information, thus the scheme is robust against decoherence. 相似文献
2.
A. Khalique G. M. Nikolopoulos G. Alber 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(3):453-464
The influence of imperfections on
achievable secret-key generation rates of quantum key distribution protocols
is investigated. As examples of relevant imperfections, we consider
tagging of Alice's qubits and dark counts at Bob's detectors, while
we focus on a powerful eavesdropping strategy which takes full advantage of
tagged signals.
It is demonstrated that error correction and privacy amplification based on
a combination of a two-way classical communication protocol and
asymmetric Calderbank-Shor-Steane codes may significantly postpone the
disastrous influence of dark counts. As a result, the
distances are increased considerably
over which a secret key can be distributed in optical fibres reliably.
Results are presented for the four-state, the six-state, and
the decoy-state protocols. 相似文献
3.
H. Aschauer H.J. Briegel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(2):171-177
We give a proof that entanglement purification, even with noisy apparatus, is sufficient to disentangle an eavesdropper (Eve)
from the communication channel. Our proof applies to all possible attacks (individual and coherent). Due to the quantum nature
of the entanglement purification protocol, it is also possible to use the obtained quantum channel for secure transmission
of quantum information.
Received 10 August 2001 and Received in final form 26 October 2001 相似文献
4.
H. Inamori N. Lütkenhaus D. Mayers 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(3):599-627
We present a complete protocol for BB84 quantum key distribution for a realistic setting (noise, loss, multi-photon signals
of the source) that covers many of todays experimental implementations. The security of this protocol is shown against an
eavesdropper having unrestricted power to manipulate the signals coherently on their path from sender to receiver. The protocol
and the security proof take into account the effects concerning the finite size of the generated key. This paper is identical
to the preprint arXiv:quant-ph/0107017, which was finalized in 2001. Therefore, some of the more recent developments, including the question of composability, are
not addressed. 相似文献
5.
Based on the idea of dense coding of three-photon entangled state and qubit transmission in blocks, we present a multiparty controlled quantum secret direct communication scheme by using Greenberger-Horne-Zeilinger state. In the present scheme, the sender transmits three bits of secret message to the receiver directly and the secret message can only be recovered by the receiver under the permission of all the controllers. All three-photon entangled states are used to transmit the secret message except those chosen for eavesdropping check and the present scheme has a high source capacity because Greenberger-Horne-Zeilinger state forms a large Hilbert space. 相似文献
6.
We analyze the security of multiparty controlled quantum secure direct communication using Greenberger-Horne-Zeilinger (GHZ) state. It is shown that the receiver, using a special property of GHZ state, can illegally obtain 33.3% of the sender’s secret without any controller’s permission. The attack strategy is demonstrated in detail and an improvement of this protocol is discussed. The idea of this attack might be instructive for the cryptanalysis of quantum cryptographic protocols. 相似文献
7.
I. M. Herbauts S. Bettelli H. Hübel M. Peev 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(2):395-406
Some MIT researchers [Phys. Rev. A
75, 042327 (2007)] have recently claimed that
their implementation of the Slutsky-Brandt attack [Phys. Rev. A
57, 2383 (1998); Phys. Rev. A 71, 042312 (2005)] to
the BB84 quantum-key-distribution (QKD) protocol puts the security of this
protocol “to the test” by simulating “the most powerful
individual-photon attack” [Phys. Rev. A 73, 012315
(2006)].
A related unfortunate news feature by a
scientific journal [G. Brumfiel, Quantum cryptography is hacked, News @ Nature (april 2007); Nature 447, 372 (2007)]
has spurred some concern in the QKD community and among the general public
by misinterpreting the implications of this work. The present article
proves the existence of a stronger individual attack on QKD protocols with
encrypted error correction, for which tight bounds are shown, and clarifies
why the claims of the news feature incorrectly suggest a contradiction with
the established “old-style” theory of BB84 individual attacks.
The full implementation of a quantum cryptographic protocol includes a
reconciliation and a privacy-amplification stage, whose choice alters in
general both the maximum extractable secret and the optimal eavesdropping
attack. The authors of [Phys. Rev. A
75, 042327 (2007)] are concerned only with the error-free
part of the so-called sifted string, and do not consider faulty bits,
which, in the version of their protocol, are discarded. When using the
provably superior reconciliation approach of encrypted error correction
(instead of error discard), the Slutsky-Brandt attack is no more optimal
and does not “threaten” the security bound derived by Lütkenhaus [Phys. Rev. A 59, 3301 (1999)].
It is shown that the method of Slutsky and collaborators [Phys. Rev. A
57, 2383 (1998)] can
be adapted to reconciliation with error correction, and that the optimal
entangling probe can be explicitly found. Moreover, this attack fills
Lütkenhaus bound, proving that it is tight (a fact which was not
previously known). 相似文献
8.
G. Benenti S. Felloni G. Strini 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(2):389-396
We study the stability under quantum noise effects of the quantum privacy amplification protocol for the purification of entanglement
in quantum cryptography. We assume that the E91 protocol is used by two communicating parties (Alice and Bob) and that the
eavesdropper Eve uses the isotropic Bužek-Hillery quantum copying machine to extract information.
Entanglement purification is then operated by Alice and Bob by means of the quantum privacy amplification protocol and we
present a systematic numerical study of the impact of all possible
single-qubit noise channels on this protocol. We find that both the qualitative behavior of the fidelity of the purified state
as a function of the number of purification steps and
the maximum level of noise that can be tolerated by the protocol strongly depend on the specific noise channel. These results
provide valuable information for experimental implementations of the quantum privacy amplification protocol. 相似文献
9.
Y. B. Sheng F. G. Deng 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,48(2):279-284
We present an efficient and economic scheme for five-party quantum
state sharing of an arbitrary m-qubit state with 2m three-particle
Greenberger-Horne-Zeilinger (GHZ) states and three-particle
GHZ-state measurements. It is more convenient than other schemes as
it only resorts to three-particle GHZ states and three-particle
joint measurement, not five-particle entanglements and five-particle
joint measurements. Moreover, this symmetric scheme is in principle
secure even though the number of the dishonest agents is more than
one. Its total efficiency approaches the maximal value. 相似文献
10.
A revised controlled deterministic secure quantum communication protocol using five-photon entangled state is proposed. It amends the security loopholes pointed by Qin et al. in [S.J. Qin, Q.Y. Wen, L.M. Meng, F.C. Zhu, Opt. Commun. 282 (2009) 2656] in the original protocol proposed by Xiu et al. in [X.M. Xiu, L. Dong, Y.J. Gao, F. Chi, Opt. Commun. 282 (2009) 333]. The security loopholes are solved by using order rearrangement of transmission photons and two-step security test. 相似文献
11.
J. Bouda M. Koniorczyk A. Varga 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(3):365-372
Channels encrypting quantum bits by the application of randomly
chosen unitary operators are studied. Quantities based on averages of
linear entropies which characterize certain aspects
of the encoding quality and the non-malleability of the
channels are introduced. The relation between the entropy of the classical key and
the choice of the encryption operators with the behaviour of these
properties is discussed. The extension of exact private quantum
channels in order to improve non-malleability via additional
encryption operators is considered. 相似文献
12.
Quantum Secret Sharing Protocol between Multiparty and Multiparty with Single Photons and Unitary Transformations 下载免费PDF全文
We propose a scheme of quantum secret sharing between Alice's group and Bob's group with single photons and unitary transformations. In the protocol, one member in Alice's group prepares a sequence of single photons in one of four different states, while other members directly encode their information on the sequence of single photons via unitary operations; after that, the last member sends the sequence of single photons to Bob's group. Then Bob's, except for the last one, do work similarly. Finally the last member in Bob's group measures the qubits. If the security of the quantum channel is guaranteed by some tests, then the qubit states sent by the last member of Alice's group can be used as key bits for secret sharing. It is shown that this scheme is safe. 相似文献
13.
P. Navez 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(2):219-228
We describe a cryptographic protocol consisting of two entangled beams of squeezed light which makes use of statistical tests
to deduce the secret key bit. The sender (Alice) encrypts a secret key by modulating the phase of the beam sent in public
by the receiver (Bob) who keeps the other beam private. The knowledge of the degree of non classical correlation between the
beam quadrature components measured in private and in public allows only Bob to decrypt the secret key. With a view towards
absolute security, we formally prove that any external intervention from an eavesdropper (Eve) during the communication process
introduces necessarily some modification susceptible to be detected. Statistical confidentiality tests are proposed to detect
the presence of Eve.
Received 12 July 2001 and Received in final form 11 November 2001 相似文献
14.
We present a tripartite quantum information splitting scheme which splits a qutrit state via two GHZ states. The scheme is then generalized to splitting a qudit state among any number of receivers. We show that this scheme is also applicable to splitting any multi-qudit entangled states. 相似文献
15.
Efficient Multiparty-to-Multiparty Quantum Secret Sharing via Continuous Variable Operations 下载免费PDF全文
The one-to-multiparty quantum secret sharing scheme [Phys. Rev. A 71 (2005) 044301] proposed recently is extended to a multiparty-to-multiparty case. Furthermore, the continuous variable operations are employed in the extended scheme to replace the specific discrete unitary operations used in the original scheme. The complete randomicity of the continuous variable characterizing the unitary operations can ensure the security of secret sharing. Moreover, the present scheme is compared with the recent similar scheme [Phys. Rev. A 72 (2005) 012304]. It is found that the efficiency of the present scheme is n times of that of the previous one. 相似文献
16.
A scheme for three-party quantum secret sharing of a private key is presented with single photons. The agent Bob first prepares a sequence of single photons with two biased bases and then sends them to the boss Alice who checks the security of the transmission with measurements and produces some decoy photons by rearranging the orders of some sample photons. Alice encodes her bits with two unitary operations on the photons and then sends them to the other agent. The security of this scheme is equivalent to that in the modified Bennett Brassard 1984 quantum key distribution protocol. Moreover, each photon can carry one bit of the private key and the intrinsic efficiency for qubits and the total efficiency both approach the maximal value 100% when the number of the bits in the key is very large. 相似文献
17.
We propose a protocol for multiparty quantum secret sharing of secure direct communication using single photons. In this protocol, random phase shift operations instead of some special discrete unitary operations used usually are employed to realize the sharing controls. The security of this protocol with respect to various kinds of attacks is discussed. Due to the complete randomicity of the phase shift characterizing the unitary operations, the security of secret sharing is therefore enhanced. 相似文献
18.
Using high-dimensional quantum error-avoiding code, we present two new quantum key distribution protocols over a collective noisy channel, i.e. six-photon and five-photon quantum error-avoiding codes. Compared with the previous protocols using four-photon and three-photon quantum error-avoiding code, the qubit efficiencies of the new protocols have increases of 16.67% and 5% respectively. In addition, the security of these protocols is analysed with a conclusion that the new protocols are much more secure than the four-photon and three-photon ones. 相似文献
19.
We propose two schemes of quantum secure direct communication (QADC) combined ideas of user authentication [Phys. Rev. A 73 (2006) 042305] and direct communication with dense coding [Phys. Rev. A. 68 (2003) 042317]. In these protocols, the privacy of authentication keys and the properties of the EPR pairs not only ensure the realization of identity authentication but also further improve the security of communication, and no secret messages are leaked even if the messages were broken. 相似文献
20.
We consider the use of qutrits in a two way deterministic quantum cryptographic protocol which exhibits a higher level of security. We analyse the security of the protocol in the context of the Intercept Resend Strategy. The protocol which transmits a qutrit is naturally limited to not utilising all the available maximally overlapping basis due to a no go theorem not unlike the universal-NOT. We further propose another protocol to generalise the protocol above against the no-go theorem. 相似文献