8,900 research outputs found
Improving the security of multiparty quantum secret splitting and quantum state sharing
A protocol for multiparty quantum secret splitting (MQSS) with an ordered
Einstein-Podolsky-Rosen (EPR) pairs and Bell state measurements is recently
proposed by Deng {\rm et al.} [Phys. Lett. A 354(2006)190]. We analyzed the
security of the protocol and found that this protocol is secure for any other
eavesdropper except for the agent Bob who adopts intercept-and-resend attack.
Bob can obtain all the information of Alice's alone without being found. We
also propose an improved version of the MQSS protocol.Comment: To appear in Phys. Lett.
Multiparty quantum secret sharing with pure entangled states and decoy photons
We present a scheme for multiparty quantum secret sharing of a private key
with pure entangled states and decoy photons. The boss, say Alice uses the
decoy photons, which are randomly in one of the four nonorthogonal
single-photon states, to prevent a potentially dishonest agent from
eavesdropping freely. This scheme requires the parties of communication to have
neither an ideal single-photon quantum source nor a maximally entangled one,
which makes this scheme more convenient than others in a practical application.
Moreover, it has the advantage of having high intrinsic efficiency for qubits
and exchanging less classical information in principle.Comment: 5 pages, no figure
Static/Dynamic Filtering for Mesh Geometry
The joint bilateral filter, which enables feature-preserving signal smoothing
according to the structural information from a guidance, has been applied for
various tasks in geometry processing. Existing methods either rely on a static
guidance that may be inconsistent with the input and lead to unsatisfactory
results, or a dynamic guidance that is automatically updated but sensitive to
noises and outliers. Inspired by recent advances in image filtering, we propose
a new geometry filtering technique called static/dynamic filter, which utilizes
both static and dynamic guidances to achieve state-of-the-art results. The
proposed filter is based on a nonlinear optimization that enforces smoothness
of the signal while preserving variations that correspond to features of
certain scales. We develop an efficient iterative solver for the problem, which
unifies existing filters that are based on static or dynamic guidances. The
filter can be applied to mesh face normals followed by vertex position update,
to achieve scale-aware and feature-preserving filtering of mesh geometry. It
also works well for other types of signals defined on mesh surfaces, such as
texture colors. Extensive experimental results demonstrate the effectiveness of
the proposed filter for various geometry processing applications such as mesh
denoising, geometry feature enhancement, and texture color filtering
Improving the security of multiparty quantum secret sharing against Trojan horse attack
We analyzed the security of the multiparty quantum secret sharing (MQSS)
protocol recently proposed by Zhang, Li and Man [Phys. Rev. A \textbf{71},
044301 (2005)] and found that this protocol is secure for any other
eavesdropper except for the agent Bob who prepares the quantum signals as he
can attack the quantum communication with a Trojan horse. That is, Bob replaces
the single-photon signal with a multi-photon one and the other agent Charlie
cannot find this cheating as she does not measure the photons before they runs
back from the boss Alice, which reveals that this MQSS protocol is not secure
for Bob. Finally, we present a possible improvement of the MQSS protocol
security with two single-photon measurements and six unitary operations.Comment: 4 pages, 2 figures; The revised version of the paper published in
Phys. Rev. A 72, 044302 (2005). A bug is modified and an addendum is adde
Efficient high-capacity quantum secret sharing with two-photon entanglement
An efficient high-capacity quantum secret sharing scheme is proposed
following some ideas in quantum dense coding with two-photon entanglement. The
message sender, Alice prepares and measures the two-photon entangled states,
and the two agents, Bob and Charlie code their information on their photons
with four local unitary operations, which makes this scheme more convenient for
the agents than others. This scheme has a high intrinsic efficiency for qubits
and a high capacity.Comment: 5 pages, no figures. A inappreciable error is correcte
Multilocus Association Testing of Quantitative Traits Based on Partial Least-Squares Analysis
Because of combining the genetic information of multiple loci, multilocus association studies (MLAS) are expected to be more powerful than single locus association studies (SLAS) in disease genes mapping. However, some researchers found that MLAS had similar or reduced power relative to SLAS, which was partly attributed to the increased degrees of freedom (dfs) in MLAS. Based on partial least-squares (PLS) analysis, we develop a MLAS approach, while avoiding large dfs in MLAS. In this approach, genotypes are first decomposed into the PLS components that not only capture majority of the genetic information of multiple loci, but also are relevant for target traits. The extracted PLS components are then regressed on target traits to detect association under multilinear regression. Simulation study based on real data from the HapMap project were used to assess the performance of our PLS-based MLAS as well as other popular multilinear regression-based MLAS approaches under various scenarios, considering genetic effects and linkage disequilibrium structure of candidate genetic regions. Using PLS-based MLAS approach, we conducted a genome-wide MLAS of lean body mass, and compared it with our previous genome-wide SLAS of lean body mass. Simulations and real data analyses results support the improved power of our PLS-based MLAS in disease genes mapping relative to other three MLAS approaches investigated in this study. We aim to provide an effective and powerful MLAS approach, which may help to overcome the limitations of SLAS in disease genes mapping
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