An Efficient Attribute-Based Signature with Application to Secure Attribute-Based Messaging System

Author(s):  
Piyi Yang ◽  
Tanveer A Zia

A set of attributes instead of a single string to represent the signer’s identity is a challenging problem under standard cryptographic assumption in the standard model. Therefore, designing a fully secure (adaptive-predicate unforgeable and perfectly private) Attribute-Based Signature (ABS) that allows a signer to choose a set of attributes is vital. Existing schemes are either too complicated or have only been proved in the generic group model. In this chapter, the authors present an efficient fully secure ABS scheme in the standard model based on q-parallel BDHE assumption, which is more practical than the generic group model used in the previous schemes. The proposed scheme is highly expressive since it allows any signer to specify claim-predicates in terms of any predicate consisting of AND, OR, and Threshold gates over the attributes in the system. ABS has found many important applications in secure communications, such as anonymous authentication systems and attribute-based messaging systems.

2003 ◽  
Vol 18 (24) ◽  
pp. 4403-4441 ◽  
Author(s):  
L. V. LAPERASHVILI ◽  
D. A. RYZHIKH ◽  
H. B. NIELSEN

Considering our (3+1)-dimensional space–time as, in some way, discrete or lattice with a parameter a = λP, where λP is the Planck length, we have investigated the additional contributions of lattice artifact monopoles to beta functions of the renormalization group equations for the running fine structure constants αi(μ) (i = 1,2,3 correspond to the U(1), SU(2) and SU(3) gauge groups of the Standard Model) in the Family Replicated Gauge Group Model (FRGGM) which is an extension of the Standard Model at high energies. It was shown that monopoles have N fam times smaller magnetic charge in FRGGM than in SM (N fam is the number of families in FRGGM). We have estimated also the enlargement of a number of fermions in FRGGM leading to the suppression of the asymptotic freedom in the non-Abelian theory. We have shown that, in contrast to the case of anti-GUT when the FRGGM undergoes the breakdown at μ = μG ~ 1018 GeV , we have the possibility of unification if the FRGGM-breakdown occurs at μG ~ 1014 GeV . By numerical calculations we obtained an example of the unification of all gauge interactions (including gravity) at the scale μ GUT ≈ 1018.4 GeV . We discussed the possibility of [ SU (5)]3 or [ SO (10)]3 (SUSY or not SUSY) unifications.


Author(s):  
Robert Hayes

This brief work tenets that inflationary genesis can be obtained within the standard model based on only a few general assumptions. These are that the origin began at a singularity of Planck length and that all quantum transitions take place within Planck time units. From these, the subsequent effects from the Pauli Exclusion Principle (PEP) and the uncertainty principle can then give rise to an inflationary origin.


2007 ◽  
Vol 22 (06) ◽  
pp. 435-447 ◽  
Author(s):  
WILLIAM A. PONCE ◽  
LUIS A. SÁNCHEZ

We carry out a systematic study of possible extensions of the standard model based on the gauge group SU (3)c⊗ SU (4)L⊗ U (1)X. We consider models with particles having exotic electric charges and also models which do not contain exotic electric charges in the gauge boson sector or in the fermion sector. For the first case an infinite number of models can, in principle, be constructed, while the restriction to non-exotic electric charges only allows for eight different anomaly-free models. Four of them are three-family models in the sense that anomalies cancel by an interplay between the three families, and another two are one-family models where anomalies cancel family by family as in the standard model. The remaining two are two-family models.


2011 ◽  
Vol 26 (27n28) ◽  
pp. 4687-4701
Author(s):  
DIETER LÜST

We consider extensions of the Standard Model based on open strings ending on D-branes, with gauge bosons due to strings attached to stacks of D-branes and chiral matter due to strings stretching between intersecting D-branes. Assuming that the fundamental string mass scale is in the TeV range and the theory is weakly coupled, we discuss possible signals of string physics at the Large Hadron Collider (LHC).


2000 ◽  
Vol 15 (19) ◽  
pp. 1221-1225 ◽  
Author(s):  
G. B. TUPPER ◽  
R. J. LINDEBAUM ◽  
R. D. VIOLLIER

We examine the phenomenology of a low-energy extension of the Standard Model, based on the gauge group SU (3) ⊗ SU (2) ⊗ U (1)⊗ SO (3), with SO(3) operating in the shadow sector. This model offers vacuum νe → νs and νμ → ντ oscillations as the solution of the solar and atmospheric neutrino problems, and it provides a neutral heavy shadow lepton X that takes the role of a cold dark matter particle.


Author(s):  
Luca Nanni

Recently, a new theory based on superluminal tunnelling has been proposed to explain the transition of highly energetic neutrinos propagating in matter to tachyonic states. In this work, we determine the possible mechanisms that lead neutrinos into a superluminal realm based on the assumption that ultrarelativistic particles travelling in matter lose part of their energy with the emission of Bremsstrahlung radiation. The obtained photons, in turn, can create neutrino-antineutrino pairs, one or both of which can be superluminal. We also prove that pair creation may occur with neutrino flavour oscillation provided that only one of them is a space-like particle. This suggests that mass oscillation and superluminal behaviour could be related phenomena. Finally, using the generalised Lorentz transformations, we formulate the Lagrangian of the kinematically allowed scattering processes. The structure of this Lagrangian is consistent with the formalism of the Standard Model. Based on this Lagrangian, at least one of the particles forming the pair must always be subluminal. The possibility that the pair creation process is mediated by a dark photon is also discussed.


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