60,235 research outputs found
A proposal for founding mistrustful quantum cryptography on coin tossing
A significant branch of classical cryptography deals with the problems which
arise when mistrustful parties need to generate, process or exchange
information. As Kilian showed a while ago, mistrustful classical cryptography
can be founded on a single protocol, oblivious transfer, from which general
secure multi-party computations can be built.
The scope of mistrustful quantum cryptography is limited by no-go theorems,
which rule out, inter alia, unconditionally secure quantum protocols for
oblivious transfer or general secure two-party computations. These theorems
apply even to protocols which take relativistic signalling constraints into
account. The best that can be hoped for, in general, are quantum protocols
computationally secure against quantum attack. I describe here a method for
building a classically certified bit commitment, and hence every other
mistrustful cryptographic task, from a secure coin tossing protocol. No
security proof is attempted, but I sketch reasons why these protocols might
resist quantum computational attack.Comment: Title altered in deference to Physical Review's fear of question
marks. Published version; references update
Adaptive Markets and the New World Order
In the adaptive markets hypothesis (AMH) intelligent but fallible investors learn from and adapt to changing economic environments. This implies that markets are not always efficient but are usually competitive and adaptive, varying in their degree of efficiency as the environment and investor population change over time. The AMH has several implications, including the possibility of negative risk premiums, alpha converging to beta, and the importance of macro factors and risk budgeting in asset allocation policies
Non-Blocking Signature of very large SOAP Messages
Data transfer and staging services are common components in Grid-based, or
more generally, in service-oriented applications. Security mechanisms play a
central role in such services, especially when they are deployed in sensitive
application fields like e-health. The adoption of WS-Security and related
standards to SOAP-based transfer services is, however, problematic as a
straightforward adoption of SOAP with MTOM introduces considerable
inefficiencies in the signature generation process when large data sets are
involved. This paper proposes a non-blocking, signature generation approach
enabling a stream-like processing with considerable performance enhancements.Comment: 13 pages, 5 figure
Non-Blocking Signature of very large SOAP Messages
Data transfer and staging services are common components in Grid-based, or
more generally, in service-oriented applications. Security mechanisms play a
central role in such services, especially when they are deployed in sensitive
application fields like e-health. The adoption of WS-Security and related
standards to SOAP-based transfer services is, however, problematic as a
straightforward adoption of SOAP with MTOM introduces considerable
inefficiencies in the signature generation process when large data sets are
involved. This paper proposes a non-blocking, signature generation approach
enabling a stream-like processing with considerable performance enhancements.Comment: 13 pages, 5 figure
Food volume estimation for quantifying dietary intake with a wearable camera
A novel food volume measurement technique is proposed in this paper for accurate quantification of the daily dietary intake of the user. The technique is based on simul- taneous localisation and mapping (SLAM), a modified version of convex hull algorithm, and a 3D mesh object reconstruction technique. This paper explores the feasibility of applying SLAM techniques for continuous food volume measurement with a monocular wearable camera. A sparse map will be generated by SLAM after capturing the images of the food item with the camera and the multiple convex hull algorithm is applied to form a 3D mesh object. The volume of the target object can then be computed based on the mesh object. Compared to previous volume measurement techniques, the proposed method can measure the food volume continuously with no prior information such as pre-defined food shape model. Experiments have been carried out to evaluate this new technique and showed the feasibility and accuracy of the proposed algorithm in measuring food volume
Dynamical Screening of Atom Confined by Finite-Width Fullerene
This is an investigation on the dynamical screening of an atom confined
within a fullerene of finite width. The two surfaces of the fullerene lead to
the presence of two surface plasmon eigenmodes. It is shown that, in the
vicinity of these two eigenfrequencies, there is a large enhancement of the
confined atom's photoabsorption rate.Comment: 10 pages, 4 figures correction of figure 2 and equation 1
Leading large-x logarithms of the quark-gluon contributions to inclusive Higgs-boson and lepton-pair production
We present all-order expressions for the leading double-logarithmic threshold
contributions to the quark-gluon coefficient functions for inclusive
Higgs-boson production in the heavy top-quark limit and for Drell-Yan
lepton-pair production. These results have been derived using the structure of
the unfactorized cross sections in dimensional regularization and the large-x
resummation of the gluon-quark and quark-gluon splitting functions. The
resummed coefficient functions, which are identical up to colour factor
replacements, are similar to their counterparts in deep-inelastic scattering
but slightly more complicated.Comment: 8 pages, LaTeX, 1 figure (.eps). DESY address until 31 August 201
Benets of tight coupled architectures for the integration of GNSS receiver and Vanet transceiver
Vehicular adhoc networks (VANETs) are one emerging type of networks that will enable a broad range of applications such as public safety, traffic management, traveler information support and entertain ment. Whether wireless access may be asynchronous or synchronous (respectively as in the upcoming IEEE 8021.11p standard or in some alternative emerging solutions), a synchronization among nodes is required. Moreover, the information on position is needed to let vehicular services work and to correctly forward the messages. As a result, timing and positioning are a strong prerequisite of VANETs. Also the diffusion of enhanced GNSS Navigators paves the way to the integration between GNSS receivers and VANET transceiv ers. This position paper presents an analysis on potential benefits coming from a tightcoupling between the two: the dissertation is meant to show to what extent Intelligent Transportation System (ITS) services could benefit from the proposed architectur
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