239 research outputs found
Inflation and Dark Matter in the Model
We discuss the possibility of unifying dark matter physics and inflation in
the model of the two-component dark matter. Inflation driven by the
two-component dark matter fields can be divided into two cases, singlet dark
matter inflation and mixed dark matter inflation, where both two-component play
the role of inflaton in the latter case. For dark matter, we focus on the mixed
dark matter inflation case. We show a viable parameter space that satisfies the
theoretical and dark matter relic density constraint in the case of successful
inflation. It turns out that the dark matter density is dominated by the light
component, which is consistent with the feature of the model of the
two-component dark matter
Interplay between dark matter and leptogenesis in a common framework
We consider the interplay between dark matter and leptogenesis in a common
framework, where three right-handed neutrinos, one fermionic dark matter and
two singlet scalars are introduced into the Standard Model. The mixing of the
two singlet scalars not only determine the dark matter relic density but also
connect right-handed neutrino with dark matter. We consider that the baryon
asymmetry is generated via the resonant leptogenesis and the right-handed
neutrino masses are at TeV level. We present a viable parameter space
satisfying relic density constraint, and the parameter space is more flexible
in the case of a larger mixing angle. We found that the existence of dark
matter in the model can not only dilute the baryon asymmetry but can also
generate a larger baryon asymmetry due to the process of dark matter
annihilation into a pair of right-handed neutrinos even though dark matter mass
is lighter than right-handed neutrino mass. The enhanced effect depends on the
dark matter mass as well as right-handed neutrino mass , and
one still can find a baryon asymmetry enhanced in the case of GeV
Leptogenesis and light scalar dark matter in a model
We discuss the possibility of light scalar dark matter in a
model, in which the dark matter carries
charge but it is a singlet in the Standard Model. We
consider the case that the right-handed neutrinos not only generate baryon
asymmetry but also are related with dark matter production. We assume that dark
matter production mainly comes from scattering associated with a pair of
right-handed neutrinos while other related processes are highly suppressed due
to the tiny charge of dark matter, and the dark
matter relic density are generated via freeze-in mechanism. A feasible
parameter space is considered and we found the correct dark matter relic
density can be obtained without influencing the result of leptogenesis, and the
allowed dark matter mass region is
Combining MILP Modeling with Algebraic Bias Evaluation for Linear Mask Search: Improved Fast Correlation Attacks on SNOW
The Mixed Integer Linear Programming (MILP) technique has been widely applied in the realm of symmetric-key cryptanalysis. In this paper, we propose a new bitwise breakdown MILP modeling strategy for describing the linear propagation rules of modular addition-based operations. We apply such new techniques to cryptanalysis of the SNOW stream cipher family and find new linear masks:
we use the MILP model to find many linear mask candidates among which the best ones are identified with particular algebraic bias evaluation techniques. For SNOW 3G, the correlation of the linear mask we found is the highest on record: such results are highly likely to be optimal according to our analysis. For SNOW 2.0, we find new masks matching the correlation record and many new sub-optimal masks applicable to improving correlation attacks. For SNOW-V/Vi, by investigating both bitwise and truncated linear masks, we find all linear masks having the highest correlation, and prove the optimum of the corresponding truncated patterns under the ``fewest active S-box preferred\u27\u27 strategy. By using the newly found linear masks, we give correlation attacks on the SNOW family with improved complexities. We emphasize that the newly proposed uniform MILP-aided framework can be potentially applied to analyze LFSR-FSM structures composed of modular addition and S-box as non-linear components
Key Filtering in Cube Attacks from the Implementation Aspect
In cube attacks, key filtering is a basic step of identifying the correct key candidates by referring to the truth tables of superpolies. When terms of superpolies get massive, the truth table lookup complexity of key filtering increases significantly. In this paper, we propose the concept of implementation dependency dividing all cube attacks into two categories: implementation dependent and implementation independent. The implementation dependent cube attacks can only be feasible when the assumption that one encryption oracle query is more complicated than one table lookup holds. On the contrary, implementation independent cube attacks remain feasible in the extreme case where encryption oracles are implemented in the full codebook manner making one encryption query equivalent to one table lookup. From this point of view, we scrutinize existing cube attack results of stream ciphers Trivium, Grain-128AEAD, Acorn and Kreyvium. As a result, many of them turn out to be implementation dependent. Combining with the degree evaluation and divide-and-conquer techniques used for superpoly recovery, we further propose new cube attack results on Kreyvium reduced to 898, 899 and 900 rounds. Such new results not only mount to the maximal number of rounds so far but also are implementation independent
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