Information leakage in three-party simultaneous quantum secure direct communication with EPR pairs

In 2007, Wang et al. [M. Y. Wang and F. L. Yan, Chin. Phys. Lett. 24 (2007) 2486] proposed a three-party simultaneous quantum secure direct communication (3P-SQSDC) scheme with EPR pairs. Recently, Chong et al. [S. K. Chong and T. Hwang, Opt. Commun. OPTICS-15438 (2010(online))] proposed an enhancement on Wang et al.'s scheme. The communications in Chong et al.'s 3P-SQSDC can be paralleled and thus their scheme has higher efficiency. However, we find that both of the schemes have the information leakage, because the legitimate parties' secret messages have a strong correlation. This kind of security loophole leads to the consequence that any eavesdropper (Eve) can directly conjecture some information about the secrets without any active attack.     

Constructions and properties of k out of n scalable secret image sharing

Recently, Wang et al. introduced a novel (2, n) scalable secret image sharing (SSIS) scheme, which can gradually reconstruct a secret image in a scalable manner in which the amount of secret information is proportional to the number of participants. However, Wang et al.’s scheme is only a simple 2-out-of-n case. In this paper, we consider (k, n)-SSIS schemes where a qualified set of participants consists of any k participants. We provide two approaches for a general construction for any k, 2 ? k ? n. For the special case k = 2, Approach 1 has the lesser shadow size than Wang et al.’s (2, n)-SSIS scheme, and Approach 2 is reduced to Wang et al.’s (2, n)-SSIS scheme. Although the authors claim that Wang et al.’s (2, n)-SSIS scheme can be easily extended to a general (k, n)-SISS scheme, actually the extension is not that easy as they claimed. For the completeness of describing the constructions and properties of a general (k, n)-SSIS scheme, both approaches are introduced in this paper.     

One color contrast enhanced infrared and visible image fusion method

Color constancy (Toet and Franken, 2003 [2]; Toet, 2003 [7]) and color contrast (Scribner et al., 2000 [21]; Lee et al., 2005 [23]) are two important topics for color image fusion. The paper focuses on the low color contrast problem of linear fusion algorithms with color transfer method. Color transfer technology is popular in infrared (IR) and visible image fusion to give the fused image a natural day-time color appearance (Toet, 2003 [7]; Wang et al., 2007 [8]; Zheng and Essock, 2008 [9]). However, in the color transfer step, all three channels of the color space are processed with the same linear mapping without color enhancement, resulting in low color contrast between the target and the background (Wang et al., 2007 [8]). Based on the characteristics of the IR image, we introduce a ratio of local to global divergence of the IR image to improve the color contrast. The enhancement ratios for both hot and cold targets are larger than one, while it tends to one for the background. As a result, the proposed method pops out both hot and cold targets in color, where hot targets will appear intense red, and cold targets will appear cyan. Subjective results show visible color contrast enhancement effects. Target detection experiments through hue and saturation components of the fused image show an improvement in the hit rate for target detection, owing to larger color distance between the target and the background.     

An enhancement on Shi et al.'s multiparty quantum secret sharing protocol

Recently, Shi et al. proposed a multiparty quantum secret sharing (QSS) using Bell states and Bell measurements. In their protocol, for sharing two classical bits, all parties have to possess two photons after entanglement swapping. This paper proposes an enhancement of Shi et al.'s protocol. Based on the idea that all parties (except dealer) possess two photons to share two classical bits, the qubit efficiency has further improved by removing the photons the dealer has to hold in Shi et al.'s protocol. Moreover, an insider attack is also prevented in the proposed scheme.     

Enhanced Multiparty Controlled QSDC Using GHZ State

Recently, Gao et al. [Opt. Commun. 283 (2010) 192] pointed out that Wang et al.'s multiparty controlled quantum secure directcommunication (CQSDC) protocol [Opt. Commun. 266 (2006)732] has the information leakage problem and proposed an improvedprotocol. However, in the improved protocol, due to the introductionof an additional random sampling to avoid the weakness, the qubitefficiency is decreased. By introducing the base changing techniqueto the random sampling in Wang et al.'s protocol, this study overcomesthe information leakage problem and provides a better qubit efficiency.     

Quantum Dialogue Protocol Based on Bell Entangled States and Single Photons

International Journal of Theoretical Physics - In this paper, inspired by Wang et al.’s deterministic secure quantum communication (DSQC) scheme (Commun. Theor. Phys. 60 (2013)...     

Cryptanalysis and improvement of multiparty quantum secret sharing schemes

A scheme of multiparty quantum secret sharing of classical messages (QSSCM) [Z.J. Zhang et al., Opt. Commun. 269 (2007) 418] was proposed. Lin et al. [S. Lin et al., Opt. Commun. 281 (2008) 4553] showed the last agent can obtain half of the secret in Z.J. Zhang's et al. three-party QSSCM scheme and gave an improved version. We further show the first agent and the last agent can obtain all the secret without introducing any error in Zhang's et al. multiparty QSSCM scheme by a special attack with quantum teleportation. We also present an improved version.     

Quantum Teleportation and Superdense Coding via W-Class States

Abstract According to the protocol of Agrawal et al., we propose a cavity QED scheme for realization of teleportation and dense coding. Instead of using EPR states and GHZ states, our scheme is more insensitive to the loss of one particle by using a W-class state as a quantum channel. Besides, our scheme is immune to thermal field, and does not require the cavity to remain in the vacuum state throughout the procedure.     

Origin of discrepancies in inelastic electron tunneling spectra of molecular junctions

We report inelastic electron tunneling spectroscopy (IETS) of multilayer molecular junctions with and without incorporated metal nanoparticles. The incorporation of metal nanoparticles into our devices leads to enhanced IET intensity and a modified line shape for some vibrational modes. The enhancement and line-shape modification are both the result of a low lying hybrid metal nanoparticle-molecule electronic level. These observations explain the apparent discrepancy between earlier IETS measurements of alkane thiolate junctions by Kushmerick et al. [Nano Lett. 4, 639 (2004)] and Wang et al. [Nano Lett. 4, 643 (2004)].     

Comment on “Quantum Key Distribution and Quantum Authentication Based on Entangled State”

Shi et al. (Phys. Lett. A 281:83–87, 2001) proposed a scheme which allows simultaneous realization of quantum key distribution and quantum authentication. However, this study points out a weakness in Shi et al.’s scheme, in which a malicious user can impersonate a legitimate participant without being detected. Furthermore, an improved scheme is proposed to avoid this weakness.     

Improving the Reversible LSB Matching Scheme Based on the Likelihood Re-Encoding Strategy

In 2018, Tseng et al. proposed a dual-image reversible embedding method based on the modified Least Significant Bit matching (LSB matching) method. This method improved on the dual-image LSB matching method proposed by Lu et al. In Lu et al.’s scheme, there are seven situations that cannot be restored and need to be modified. Furthermore, the scheme uses two pixels to conceal four secret bits. The maximum modification of each pixel, in Lu et al.’s scheme, is two. To decrease the modification, Tseng et al. use one pixel to embed two secret bits and allow the maximum modification to decrease from two to one such that the image quality can be improved. This study enhances Tseng et al.’s method by re-encoding the modified rule table based on the probability of each hiding combination. The scheme analyzes the frequency occurrence of each combination and sets the lowest modified codes to the highest frequency case to significantly reduce the amount of modification. Experimental results show that better image quality is obtained using our method under the same amount of hiding payload.     

Improvement on ‘Multiparty Quantum Key Agreement with Four-Qubit Symmetric W State’

Recently, Wang et al. (Int J Theo Phys: pp. 3716–3726, 2018) proposed a multiparty quantum key agreement scheme with four-particles W state. Their protocol uses the delayed measurement technique, the block transmission technique, and the single decoy photon technique to determine a shared secret key between three or more participants. They claimed that their protocol could resist both internal/participant and external attacks. However, this work indicates that two dishonest participants can collude to get the private data of a participant who executes the protocol honestly. To solve this issue, a simple modification is suggested in this work.

     

Modification Attack on QSDC with Authentication and the Improvement

Recently, Yu et al. [Int. J. Theor. Phys., 2012, doi:10.1007/s10773-012-1336-y] proposed a quantum secure direct communication (QSDC) with authentication using two non-orthogonal states. This study points out a pitfall in Yu et al.’s scheme, in which an eavesdropper can deliberately modify the message without being detected. Furthermore, an enhanced scheme is proposed to avoid the modification attack.     

The problems with M

M² is now widely used to characterize the quality of laser radiation. In the paraxial approach the inequality M²1 holds, if M² is defined by the second moments. Nevertheless, in some publications M²<1 is presented, either theoretically or experimentally (Wang et al., Optik 1995;100(1):8; Lu et al., Optik 1995;100(2):91; Wang et al., Optics and Laser Technology 1999;31:151). In particular, it is stated that for a superposition of axially shifted Gaussian spherical beams, M² can become smaller than one (Wang et al., Optics and Laser Technology 1999;31:151). These problems with M² are briefly summarized.     

Economical multiparty simultaneous quantum identity authentication based on Greenberger--Horne--Zeilinger states

A multiparty simultaneous quantum identity authentication protocol based on Greenberger--Horne--Zeilinger (GHZ) states is proposed. The multi-user can be authenticated by a trusted third party (TTP) simultaneously. Compared with the scheme proposed recently (Wang et al 2006, Chin. Phys. Lett. 23(9) 2360), the proposed scheme has the advantages of consuming fewer quantum and classical resources and lessening the difficulty and intensity of necessary operations.     

Sensitivity enhancement in multiple-quantum NMR experiments with CPMG detection

We present a modified multiple-quantum (MQ) experiment, which implements the Carr-Purcell-Meiboom-Gill (CPMG) detection scheme in the static MQ NMR experiment proposed by W. S. Warren et al. (1980, J. Chem. Phys.73, 2084-2099) and exploited further by O. N. Antzutkin and R. Tycko (1999, J. Chem. Phys.110, 2749-2752). It is demonstrated that a significant enhancement in the sensitivity can be achieved by acquiring echo trains in the MQ experiments for static powder samples. The modified scheme employing the CPMG detection was superior to the original MQ experiment, in particular for the carbonyl carbon with a very large chemical shift anisotropy.     

A harmonious unifying hybrid preferential model and its universal properties for complex dynamical networks

To describe the real world which is a harmonious unification world with both de- terminism and randomness, we propose a harmonious unifying hybrid preferential model (HUHPM) of a certain class of complex dynamical networks. HUHPM is gov- erned only by the total hybrid ratio d/r according to the practical need. As some typical examples, the concepts and methods of the HUHPM are applied to the un-weighted BA model proposed by Barabási et al., the weighted BBV model pro- posed by Barat et al. and the weighted TDE model proposed by Wang et al. to get the so-called HUHPM-BA network, HUHPM-BBV network and HUHPM-TDE network. These HUHPM networks are investigated both analytically and numerically. It is found that the HUHPM reveals several universal properties, which more approach to the real-world networks for both un-weighted and weighted networks and have potential for applications.     

Eavesdropping on Semi-Quantum Secret Sharing Scheme of Specific Bits

In a recent paper, Xie et al. (Int. Theor. Phys. 54, 3819–3824, 2015) proposed a semi-quantum secret sharing scheme based on specific bits. In this paper, a simple attack strategy (intercept-resend attack) is shown to prove that the Xie et al.’s scheme is not secure for a dishonest participant, and an improved protocol based on GHZ state is proposed. The improved protocol is secure and improves the efficiency of the previous one.     

Bell's theorem and an explicit stochastic local hidden-variable model

Motivated by a paper by Barut and Meystre, Bohm's EPR gedanken experiment performed with classical and spin-s particles is considered, and the applicability of Bell's theorem to these cases is discussed. The classical model presented by Barut and Meystre is modified to become a stochastic local hidden-variable model reproducing the results of an EPR experiment of the type performed by Aspect et al.     

利用一个三粒子W态隐形传送N粒子GHZ态

杨洪钦等提出一个用两个三粒子W态作为量子信道将N粒子GHZ态从发送者传送给两个接收者中任意一个的量子隐形传送方案. 给出其理论分析,并提出了一个仅用一个三粒子W态作为量子信道将N粒子GHZ态传送给两个接收者之一的量子隐形传送的方案. 关键词： 隐形传态 GHZ态 W态量子信道