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1.
An efficient quantum secure direct communication protocol is presented over the amplitude damping channel. The protocol encodes
logical bits in two-qubit noiseless states, and so it can function over a quantum channel subjected to collective amplitude
damping. The feature of this protocol is that the sender encodes the secret directly on the quantum states, the receiver decodes
the secret by performing determinate measurements, and there is no basis mismatch. The transmission’s safety is ensured by
the nonorthogonality of the noiseless states traveling forward and backward on the quantum channel. Moreover, we construct
the efficient quantum circuits to implement channel encoding and information encoding by means of primitive operations in
quantum computation.
Supported by the National Natural Science Foundation of China (Grant Nos. 60873191 and 60821001), the Specialized Research
Fund for the Doctoral Program of Higher Education (Grant No. 200800131016), the Natural Science Foundation of Beijing (Grant
No. 4072020), the National Laboratory for Modern Communications Science Foundation of China (Grant No. 9140C1101010601), and
the ISN Open Foundation 相似文献
2.
The way to compare the efficiencies of different detect strategies (DSs) in the “ping-pong” protocol is studied. The trade-off
between information gain and disturbance is calculated and compared for different DSs. The comparison result primely tallies
with our intuitional analysis. It is shown that the analysis of this trade-off is a feasible way to compare the performances
of different DSs in theory.
Supported by the National High Technology Research and Development Program of China (Grant No. 2006AA01Z419), the National
Natural Science Foundation of China (Grant Nos. 90604023 and 6087319), the National Laboratory for Modern Communications Science
Foundation of China (Grant No. 9140C1101010601), the Natural Science Foundation of Beijing (Grant No. 4072020), and the ISN
Open Foundation. 相似文献
3.
From the perspective of information theory and cryptography, the security of two quantum dialogue protocols and a bidirectional
quantum secure direct communication (QSDC) protocol was analyzed, and it was pointed out that the transmitted information
would be partly leaked out in them. That is, any eavesdropper can elicit some information about the secrets from the public
annunciations of the legal users. This phenomenon should have been strictly forbidden in a quantum secure communication. In
fact, this problem exists in quite a few recent proposals and, therefore, it deserves more research attention in the following
related study.
Supported by the National High Technology Research and Development Program of China (Grant No. 2006AA01Z419), the National
Natural Science Foundation of China (Grant Nos. 90604023 and 60373059), the National Research Foundation for the Doctoral
Program of Higher Education of China (Grant No. 20040013007), the National Laboratory for Modern Communications Science Foundation
of China (Grant No. 9140C1101010601), the Natural Science Foundation of Beijing (Grant No. 4072020) and the ISN Open Foundation 相似文献
4.
A threshold proxy quantum signature scheme with threshold shared verification is proposed. An original signer could authorize
a group as its proxy signers. Then only t or more of n persons in the proxy group can generate the proxy signature on behalf of the original signer and any t − 1 or fewer ones cannot do that. When the proxy signature needs to be verified, any t or more of n persons belonging to the verification group can verify the message and any t − 1 or fewer ones cannot verify the validity of the proxy signature.
Supported by the National Basic Research Program of China (973 Program)(Grant No. 2007CB311100), the National High-Technology
Research and Development Program of China (Grant Nos. 2006AA01Z419 and 20060101Z4015), the Major Research Plan of the National
Natural Science Foundation of China (Grant No. 90604023), the Scientific Research Common Program of Beijing Municipal Commission
of Education (Grant No. KM200810005004), the Scientific Research Foundation for the Youth of Beijing University of Technology
(Grant No. 97007016200701), the Doctoral Scientific Research Activation Foundation of Beijing University of Technology (Grant
No. 52007016200702), and the National Laboratory for Modern Communications Science Foundation of China (Grant No. 9140C1101010601) 相似文献
5.
In most situations, the signer is generally a single person. However, when the message is written on behalf of an organization,
a valid message may require the approval or consent of several persons. Threshold signature is a solution to this problem.
Generally speaking, as an authority which can be trusted by all members does not exist, a threshold signature scheme without
a trusted party appears more attractive. Following some ideas of the classical Shamir’s threshold signature scheme, a quantum
threshold group signature one is proposed. In the proposed scheme, only t or more of n persons in the group can generate the group signature and any t − 1 or fewer ones cannot do that. In the verification phase, any t or more of n signature receivers can verify the message and any t − 1 or fewer receivers cannot verify the validity of the signature.
Supported by the National Basic Research Program of China (973 Program)(Grant No. 2007CB311100), the National High-Technology
Research and Development Program of China (Grant Nos. 2006AA01Z419 and 2006AA01Z440), the Major Research Plan of the National
Natural Science Foundation of China (Grant No. 90604023), the Scientific Research Common Program of Beijing Municipal Commission
of Education (Grant No. KM200810005004), the Scientific Research Foundation for the Youth of Beijing University of Technology
(Grant No. 97007016200701), the Doctoral Scientific Research Activation Foundation of Beijing University of Technology (Grant
No. 52007016200702), the ISN Open Foundation, and the National Laboratory for Modern Communications Science Foundation of
China (Grant No. 9140C1101010601) 相似文献
6.
Two multiparty simultaneous quantum identity authentication (MSQIA) protocols based on secret sharing are presented. All the
users can be authenticated by a trusted third party (TTP) simultaneously. In the first protocol, the TTP shares a random key
K with all the users using quantum secret sharing. The ith share acts as the authentication key of the ith user. When it is necessary to perform MSQIA, the TTP generates a random number R secretly and sends a sequence of single photons encoded with K and R to all the users. According to his share, each user performs the corresponding unitary operations on the single photon sequence
sequentially. At last, the TTP can judge whether the impersonator exists. The second protocol is a modified version with a
circular structure. The two protocols can be efficiently used for MSQIA in a network. They are feasible with current technology.
Supported by the National Basic Research Program of China (973 Program) (Grant No. 2007CB311100), the National High Technology
Research and Development Program of China (Grant Nos. 2006AA01Z419 and 20060101Z4015), the Major Research Plan of the National
Natural Science Foundation of China (Grant No. 90604023), the Scientific Research Common Program of Beijing Municipal Commission
of Education (Grant No. KM200810005004), the Scientific Research Foundation for the Youth of Beijing University of Technology
(Grant No. 97007016200701), the National Research Foundation for the Doctoral Program of Higher Education of China (Grant
No. 20040013007), the National Laboratory for Modern Communications Science Foundation of China (Grant No. 9140C1101010601),
and the Doctor Scientific Research Activation Foundation of Beijing University of Technology (Grant No. 52007016200702) 相似文献
7.
Hawking radiation can be viewed as a process of quantum tunneling near the black hole horizon. When a particle with angular
momentum L ≠ ωa tunnels across the event horizon of Kerr or Kerr-Newman black hole, the angular momentum per unit mass a should be changed. The emission rate of the massless particles under this general case is calculated, and the result is consistent
with an underlying unitary theory.
Supported by the National Natural Science Foundation of China (Grant No. 10773002) and the National Basic Research Program
of China (Grant No. 2003CB716302) 相似文献
8.
YANG YuGuang WEN QiaoYan & ZHU FuChen School of Computer Beijing University of Technology Beijing China State Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing China School of Science Beijing University of Posts Telecommunications Beijing China National Key Laboratory for Modern Communications Chengdu China 《中国科学G辑(英文版)》2007,50(3):331-338
An efficient quantum secret sharing protocol with orthogonal product states in the 33 Hilbert space is presented. The particles in the orthogonal product states form two particle sequences. One sequence is sent to Bob and the other is sent to Charlie after rearranging the particle orders. With the help of Alice, Bob and Charlie make the corresponding local measurement to obtain the information of the or- thogonal product states prepared. This protocol has many distinct features such as great capacity and high efficiency. 相似文献
9.
A quantum secret sharing scheme between an m-party group and an n-party group is proposed using three conjugate bases. A sequence of single photons, each of which is prepared in one of the
six states, is used directly to encode classical information in the quantum secret sharing process. In this scheme, each of
all m members in group 1 chooses randomly his/her own secret key individually and independently, and directly encodes his/her respective
secret information on the states of single photons via unitary operations, then the last one sends 1/n of the resulting qubits to each member of group 2. By measuring their respective qubits, all members in group 2 share the
secret information shared by all members in group 1. It renders impossible a Trojan horse attack with a multi-photon signal,
a fake-signal attack with EPR pairs, an attack with single photons, and an attack with invisible photons. We give the upper
bounds on the average success probabilities for dishonest agent eavesdropping encryption using the fake-signal attack with
any two-particle entangled states.
Supported by the National Natural Science Foundation of China (Grant No. 10671054), the Key Project of Science and Technology
Research of Education Ministry of China (Grant No. 207011) and the Natural Science Foundation of Hebei Province, China (Grant
Nos. 07M006 and F2009000311) 相似文献
10.
For the first time, a threshold quantum secure direct communication (TQSDC) scheme is presented. Similar to the classical Shamir's secret sharing scheme, the sender makes n shares, S1, …, Sn of secret key K and each receiver keeps a share secretly. If the sender wants to send a secret message M to the receivers, he en-codes the information of K and M on a single photon sequence and sends it to one of the receivers. According to the secret shares, the t receivers sequentially per-form the corresponding unitary operations on the single photon sequence and ob-tain the secret message M. The shared shares may be reusable if it can be judged that there is no eavesdropper in line. We discuss that our protocol is feasible with current technology. 相似文献
11.
The generalized uncertainty relation is introduced to calculate the quantum statistical entropy corresponding to cosmic horizon.
By using the new equation of state density motivated by the generalized uncertainty relation, we discuss entropies of Bose
field and Fermi field on the background of five-dimensional spacetime. In our calculation, we need not introduce cutoff. There
is no divergent logarithmic term in the original brick-wall method. And it is obtained that the quantum statistical entropy
corresponding to cosmic horizon is proportional to the area of the horizon. Further it is shown that the entropy corresponding
to cosmic horizon is the entropy of quantum state on the surface of horizon. The black hole’s entropy is the intrinsic property
of the black hole. The entropy is a quantum effect. In our calculation, by using the quantum statistical method, we obtain
the partition function of Bose field and Fermi field on the background of five-dimensional spacetime. We provide a way to
study the quantum statistical entropy corresponding to cosmic horizon in the higher-dimensional spacetime.
Supported by the National Natural Science Foundation of China (Grant No. 10374075) and the Natural Science Foundation of Shanxi
Province, China (Grant No. 2006011012) 相似文献
12.
We present the lowest order quantum correction to the semiclassical Boltzmann distribution function, and the equation satisfied
by this correction is given. Our equation for the quantum correction is obtained from the conventional quantum Boltzmann equation
by explicitly expressing the Planck constant in the gradient approximation, and the quantum Wigner distribution function is
expanded in powers of Planck constant, too. The negative quantum correlation in the Wigner distribution function which is
just the quantum correction terms is naturally singled out, thus obviating the need for the Husimi’s coarse grain averaging
that is usually done to remove the negative quantum part of the Wigner distribution function. We also discuss the classical
limit of quantum thermodynamic entropy in the above framework.
Supported by the National Natural Science Foundation of China (Grant No. 10404037) and the Scientific Research Fund of GUCAS
(Grant No. 055101BM03) 相似文献
13.
A protocol of quantum secret sharing between multiparty and multiparty with four states was presented. It was shown that this
protocol can nullify the Trojan horse attack with a multi-photon signal, the fake-signal attack with Einstein-Podolsky-Rosen
pairs, the attack with single photons, and the attack with invisible photons. In addition, the upper bounds of the average
success probabilities were given for dishonest agent eavesdropping encryption using the fake-signal attack with any two-particle
entangled states.
Supported by the National Natural Science Foundation of China (Grant No. 10671054), the Key Project of Science and Technology
Research of Education Ministry of China (Grant No. 207011) and the Natural Science Foundation of Hebei Province, China (Grant
Nos. A2005000140 and 07M006) 相似文献
14.
The coherent-entangled state |α, x; λ> with real parameters λ is proposed in the two-mode Fock space, which exhibits the properties of both the coherent and entangled states. The completeness relation of |α, x; λ> is proved by virtue of the technique of integral within an ordered product of operators. The corresponding squeezing operator is derived, with its own squeezing properties. Furthermore, generalized P-representation in the coherent-entangled state is constructed. Finally, it is revealed that superp... 相似文献
15.
It is a simple introduction to quantum entanglement and quantum operations. The authors focus on some applications of quantum
entanglement and relations between two-qubit entangled states and unitary operations. It includes remote state preparation
by using any pure entangled states, nonlocal operation implementation using entangled states, entanglement capacity of two-qubit
gates and two-qubit gates construction.
Supported by the National Fundamental Research Program of China (Grant No. 2001CB309306), the National Natural Science Foundation
of China (Grant Nos. 60621064 and 10674127) and the Innovation Funds from Chinese Academy of Sciences 相似文献
16.
A threshold quantum secret sharing (TQSS) scheme between multi-party and multi-party was proposed using a sequence of single
photons, which is useful and efficient when the parties of communication are not all present. We described the process of
this TQSS scheme and discussed its security. It was shown that entanglement is not necessary for quantum secret sharing. Moreover,
the theoretic efficiency was improved to approach 100% as almost all the instances can be used for generating the private
key, and each photon can carry one bit of information. This protocol is feasible with the present-day technique.
Supported by the National Basic Research Program of China (973 Program)(Grant No. 2007CB311100), the National High-Technology
Research and Development Program of China (Grant Nos. 2006AA01Z419 and 2006AA01Z440), the Major Research Plan of the National
Natural Science Foundation of China (Grant No. 90604023), the Scientific Research Common Program of Beijing Municipal Commission
of Education (Grant No. KM200810005004), the Scientific Research Foundation for the Youth of Beijing University of Technology
(Grant No. 97007016200701), the Doctoral Scientific Research Activation Foundation of Beijing University of Technology (Grant
No. 52007016200702), the ISN Open Foundation, and the National Laboratory for Modern Communications Science Foundation of
China (Grant No. 9140C1101010601) 相似文献
17.
On SrTiO3 single crystal substrate, by using the pulsed electron deposition technique, the high-quality electron doped Nd1.85Ce0.15CuO4−δ
superconducting film was successfully fabricated. After careful study on the R-T curves of the obtained samples deposited with different substrate temperatures, thicknesses, annealing methods and pulse
frequencies, the effects of them on the superconductivity of the films were found, and the reasons were also analyzed. Additionally,
by using the same model of the pulsed laser deposition technique, the relation between the target-to-substrate distance and
the deposition pressure was drawn out as a quantitative one.
Supported by the Key Project of Zhejiang Provincial Natural Science Foundation (Grant No. Z605131), the ‘100 Talents Project’
of Chinese Academy of Sciences, the Creative Research Group of National Natural Science Foundation of China (Grant No. 60321001)
and the National Natural Science Foundation of China (Grant No. 60571029) 相似文献
18.
CdS/α-Fe2O3 hierarchical nanostructures, where the CdS nanorods grow irregularly on the side surface of α-Fe2O3 nanorods, were synthesized via a three-step process. The diameters and lengths of CdS nanorods can be tuned by changing the
ethylenediamine (EDA) and Cd ion concentrations. The magnetic investigations by superconducting quantum interference device
indicate that the hierarchical nanostructures have an Morin transition at lower temperature (230 K) than that of the single
bulk α-Fe2O3 materials (263 K). Importantly, the hierarchical nanostructures exhibit weakly ferromagnetic characteristics at 300 K. A
sharp peak assigned to the surface trap induced emission are observed in room temperature PL spectra. Combining with the optoelectronic
properties of CdS, the CdS/α-Fe2O3 hierarchical nanostructures may be used as multi-functional materials for optoelectronic and magnetic devices.
Supported by the National Natural Science Foundation of China (Grant Nos. 50772025 and 50872159), the Ministry of Science
and Technology of China (Grant No. 2008DFR20420), the China Postdoctoral Science Foundation (Grant Nos. 20060400042 and 200801044),
the Natural Science Foundation of Heilongjiang Province, China (Grant No. F200828), the Specialized Research Fund for the
Doctoral Program of Higher Education of China (Grant No. 20070217002), and the Innovation Foundation of Harbin City (Grant
No. RC2006QN017016) 相似文献
19.
Using the spin networks and the asymptotic quasinormal mode frequencies of black holes given by loop quantum gravity, the
minimum horizon area gap is obtained. Then the quantum area spectrum of black holes is derived and the black hole entropy
is a realized quantization. The results show that the black hole entropy given by loop quantum gravity is in full accord with
the Bekenstein-Hawking entropy with a suitable Immirzi.
Supported by the National Natural Science Foundation of China (Grant No. 10773002) 相似文献
20.
We present a scheme for probabilistic remote preparation of a d-dimensional equatorial quantum state. In the scheme, a bipartite d-dimensional partial entangled state is used as the quantum channel, and the single-qudit projective measurement and appropriate
unitary transformation are needed. As a special, the remote preparation in three dimension is studied.
The project supported Natural Science Foundation of Education Bureau of Jiangsu Province of China (Grant No 05 KJD 140035
and 06 KJD 520027). 相似文献