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Your Code Is My Code: Exploiting a Common Weakness in OAuth 2.0 Implementations
Get PDFMany millions of users routinely use their Google, Facebook and Microsoft accounts to log inĂÂ to websites supporting OAuth 2.0-based single sign on. The security of OAuth 2.0 is therefore of critical importance, and it has been widely examined both in theory and in practice. In this paper we disclose a new class of practical attacks on OAuth 2.0 implementations, which we call Partial Redirection URI Manipulation Attacks. An attack of this type can be used by an attacker to gain a victim userâs OAuth 2.0 code (a token representing a right to access user data) without the userâs knowledge; this code can then be used to impersonate the user to the relevant relying party website. We examined 27 leading OAuth 2.0 identity providers, and found that 19 of them are vulnerable to these attacks
Cross sections for pentaquark baryon production from protons in reactions induced by hadrons and photons
Get PDFUsing hadronic Lagrangians that include the interaction of pentaquark
baryon with and , we evaluate the cross sections for its
production from meson-proton, proton-proton, and photon-proton reactions near
threshold. With empirical coupling constants and form factors, the predicted
cross sections are about 1.5 mb in kaon-proton reactions, 0.1 mb in rho-nucleon
reactions, 0.05 mb in pion-nucleon reactions, 20 b in proton-proton
reactions, and 40 nb in photon-proton reactions.Comment: 14 pages, 7 figure
Critical scaling of icosahedral medium-range order in CuZr metallic glass-forming liquids
Full text linkThe temperature evolution of icosahedral medium-range order formed by
interpenetrating icosahedra in CuZr metallic glass-forming liquids was
investigated via molecular dynamics simulations. Scaling analysis based on
percolation theory was employed, and it is found that the size distribution of
clusters formed by the central atoms of icosahedra at various temperatures
follows a very good scaling law with the cluster number density scaled by
and the cluster size scaled by ,
respectively. Here is scaling crossover-temperature. and
are scaling exponents. The critical scaling behaviour suggests that there would
be a structural phase transition manifested by percolation of locally favoured
structures underlying the glass transition, if the liquid could be cooled
slowly enough but without crystallization intervening. Furthermore, it is
revealed that when icosahedral short-range order (ISRO) extends to medium-range
length scale by connection, the atomic configurations of ISROs will be
optimized from distorted ones towards more regular ones gradually, which
significantly lowers the energies of ISROs and introduces geometric frustration
simultaneously. Both factors make key impacts on the drastic dynamic slowdown
of supercooled liquids. Our findings provide direct structure-property
relationship for understanding the nature of glass transition.Comment: 8 pages, 4 figures; Renamed, Massive Revisions, Scientific Reports
Accepte
Implantable RF-coiled chip packaging
Get PDFIn this paper, we present an embedded chip integration
technology that utilizes silicon housings and flexible
parylene radio frequency (RF) coils. As a demonstration
of this technology, a flexible parylene RF coil has been
integrated with an RF identification (RFID) chip. The coil
has an inductance of 16 ÎŒH, with two layers of metal
completely encapsulated in parylene-C. The functionality
of the embedded chip is verified using an RFID reader
module. Accelerated-lifetime soak testing has been
performed in saline, and the results show that the silicon
chip is well protected and the lifetime of our
parylene-encapsulated RF coil at 37 °C is more than 20
years
A cusp electron gun for millimeter wave gyrodevices
Get PDFThe experimental results of a thermionic cusp electron gun, to drive millimeter and submillimeter wave harmonic gyrodevices, are reported in this paper. Using a "smooth" magnetic field reversal formed by two coils this gun generated an annular-shaped, axis-encircling electron beam with 1.5 A current, and an adjustable velocity ratio alpha of up to 1.56 at a beam voltage of 40 kV. The beam cross-sectional shape and transported beam current were measured by a witness plate technique and Faraday cup, respectively. These measured results were found to be in excellent agreement with the simulated results using the three-dimensional code MAGIC
Plasmon geometric phase and plasmon Hall shift
Full text linkThe collective plasmonic modes of a metal comprise a pattern of charge
density and tightly-bound electric fields that oscillate in lock-step to yield
enhanced light-matter interaction. Here we show that metals with non-zero Hall
conductivity host plasmons with a fine internal structure: they are
characterized by a current density configuration that sharply departs from that
of ordinary zero Hall conductivity metals. This non-trivial internal structure
dramatically enriches the dynamics of plasmon propagation, enabling plasmon
wavepackets to acquire geometric phases as they scatter. Strikingly, at
boundaries these phases accumulate allowing plasmon waves that reflect off to
experience a non-reciprocal parallel shift along the boundary displacing the
incident and reflected plasmon trajectories. This plasmon Hall shift, tunable
by Hall conductivity as well as plasmon wavelength, displays the chirality of
the plasmon's current distribution and can be probed by near-field photonics
techniques. Anomalous plasmon dynamics provide a real-space window into the
inner structure of plasmon bands, as well as new means for directing plasmonic
beams
Large optical conductivity of Dirac semimetal Fermi arc surfaces states
Full text linkFermi arc surface states, a hallmark of topological Dirac semimetals, can
host carriers that exhibit unusual dynamics distinct from that of their parent
bulk. Here we find that Fermi arc carriers in intrinsic Dirac semimetals
possess a strong and anisotropic light matter interaction. This is
characterized by a large Fermi arc optical conductivity when light is polarized
transverse to the Fermi arc; when light is polarized along the Fermi arc, Fermi
arc optical conductivity is significantly muted. The large surface spectral
weight is locked to the wide separation between Dirac nodes and persists as a
large Drude weight of Fermi arc carriers when the system is doped. As a result,
large and anisotropic Fermi arc conductivity provides a novel means of
optically interrogating the topological surfaces states of Dirac semimetals.Comment: 8 pages, 3 figure
Instrumentation of a high-sensitivity microwave vector detection system for low-temperature applications
Full text linkWe present the design and the circuit details of a high-sensitivity microwave
vector detection system, which is aiming for studying the low-dimensional
electron system embedded in the slots of a coplanar waveguide at low
temperatures. The coplanar waveguide sample is placed inside a phase-locked
loop; the phase change of the sample may cause a corresponding change in the
operation frequency, which can be measured precisely. We also employ a
double-pulse modulation on the microwave signals, which comprises a fast pulse
modulation for gated averaging and a slow pulse modulation for lock-in
detection. In measurements on real samples at low temperatures, this system
provides much better resolutions in both amplitude and phase than most of the
conventional vector analyzers at power levels below -65 dBm.Comment: 7 pages, 11 figures, 1 table, lette
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