79 research outputs found

    SkyEye: A Traceable Scheme for Blockchain

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    Many studies focus on the blockchain privacy protection. Unfortunately, the privacy protection brings some issues (e.g., money-laundering problem). Tracing users\u27 identities is a critical step in addressing these issues. When each user\u27s identity in the blockchain data is determined, the regulator can do some regulatory operations (such as Big Data analysis) to decide who should be punished or who should own the lost data. In this paper, we propose SkyEye, a traceable scheme for blockchain, that can be applied to a class of blockchain application. SkyEye enables the regulator to trace users\u27 identities. Moreover, we demonstrate the security of SkyEye under specific cryptographic assumptions. Finally, we implement two prototypes of SkyEye, and evaluate the running time and related data storage requirements by performing the aforementioned prototypes

    A Blockchain Traceable Scheme with Oversight Function

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    Many blockchain researches focus on the privacy protection. However, criminals can leverage strong privacy protection of the blockchain to do illegal crimes (such as ransomware) without being punished. These crimes have caused huge losses to society and users. Implementing identity tracing is an important step in dealing with issues arising from privacy protection. In this paper, we propose a blockchain traceable scheme with oversight function (BTSOF). The design of BTSOF builds on SkyEye (Tianjun Ma et al., Cryptology ePrint Archive 2020). In BTSOF, the regulator must obtain the consent of the committee to enable tracing. Moreover, we construct a non-interactive verifiable multi-secret sharing scheme (VMSS scheme) and leverage the VMSS scheme to design a distributed multi-key generation (DMKG) protocol for the Cramer-Shoup public key encryption scheme. The DMKG protocol is used in the design of BTSOF. We provide the security definition and security proof of the VMSS scheme and DMKG protocol

    The effect of waste engine oil and waste polyethylene on UV aging resistance of asphalt.

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    Waste engine oil (WEO) and waste polyethylene (WPE) are two common wastes, which are easy to pollute the environment. As the primary material in road construction, natural asphalt is a non-renewable energy source and asphalt is vulnerable to ultraviolet (UV) radiation during the service life. It results in degradation of asphalt pavement performance. In this paper, 22 wt % to 82 wt % of WEO and WPE were used to modify asphalts and the UV aging simulation experiment was carried out. The physical parameters of asphalts before the UV aging experiment show that the asphalt containing 42 wt % WPE and 62 wt % WEO mixture (42 wt % WPE + 62 wt % WEO) has similar physical properties with that of the matrix asphalt. Besides, gel permeation chromatography (GPC) verifies that the molecular weight distribution of the asphalt containing 42 wt % WPE + 62 wt % WEO is close to that of the matrix asphalt. The storage stability test shows that 42 wt % WPE + 62 wt % WEO has good compatibility with the matrix asphalt. The functional groups and micro-morphology of asphalts before and after the UV aging experiment were investigated by Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). FTIR results display that 42 wt % WPE + 62 wt % WEO can effectively reduce the formation of carbonyl and sulfoxide functional groups. AFM shows that 42 wt % WPE + 62 wt % WEO can also retard the formation of a bee-like structure in asphalt after the UV aging experiment. Based on the above results, it can be concluded that WEO and WPE mixture can replace part of asphalt and improve the UV aging resistance of asphalt

    Synetgy: Algorithm-hardware Co-design for ConvNet Accelerators on Embedded FPGAs

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    Using FPGAs to accelerate ConvNets has attracted significant attention in recent years. However, FPGA accelerator design has not leveraged the latest progress of ConvNets. As a result, the key application characteristics such as frames-per-second (FPS) are ignored in favor of simply counting GOPs, and results on accuracy, which is critical to application success, are often not even reported. In this work, we adopt an algorithm-hardware co-design approach to develop a ConvNet accelerator called Synetgy and a novel ConvNet model called DiracDeltaNet†^{\dagger}. Both the accelerator and ConvNet are tailored to FPGA requirements. DiracDeltaNet, as the name suggests, is a ConvNet with only 1×11\times 1 convolutions while spatial convolutions are replaced by more efficient shift operations. DiracDeltaNet achieves competitive accuracy on ImageNet (88.7\% top-5), but with 42×\times fewer parameters and 48×\times fewer OPs than VGG16. We further quantize DiracDeltaNet's weights to 4-bit and activations to 4-bits, with less than 1\% accuracy loss. These quantizations exploit well the nature of FPGA hardware. In short, DiracDeltaNet's small model size, low computational OP count, low precision and simplified operators allow us to co-design a highly customized computing unit for an FPGA. We implement the computing units for DiracDeltaNet on an Ultra96 SoC system through high-level synthesis. Our accelerator's final top-5 accuracy of 88.1\% on ImageNet, is higher than all the previously reported embedded FPGA accelerators. In addition, the accelerator reaches an inference speed of 66.3 FPS on the ImageNet classification task, surpassing prior works with similar accuracy by at least 11.6×\times.Comment: Update to the latest result

    The Maximal U(1)LU(1)_L Inverse Seesaw from d=5d=5 Operator and Oscillating Asymmetric Sneutrino Dark Matter

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    The maximal U(1)LU(1)_L supersymmetric inverse seesaw mechanism (MLLSIS) provides a natural way to relate asymmetric dark matter (ADM) with neutrino physics. In this paper we point out that, MLLSIS is a natural outcome if one dynamically realizes the inverse seesaw mechanism in the next-to minimal supersymmetric standard model (NMSSM) via the dimension-five operator (N)2S2/M∗(N)^2S^2/M_*, with SS the NMSSM singlet developing TeV scale VEV; it slightly violates lepton number due to the suppression by the fundamental scale M∗M_*, thus preserving U(1)LU(1)_L maximally. The resulting sneutrino is a distinguishable ADM candidate, oscillating and favored to have weak scale mass. A fairly large annihilating cross section of such a heavy ADM is available due to the presence of singlet.Comment: journal versio

    Background Dependent Lorentz Violation: Natural Solutions to the Theoretical Challenges of the OPERA Experiment

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    To explain both the OPERA experiment and all the known phenomenological constraints/observations on Lorentz violation, the Background Dependent Lorentz Violation (BDLV) has been proposed. We study the BDLV in a model independent way, and conjecture that there may exist a "Dream Special Relativity Theory", where all the Standard Model (SM) particles can be subluminal due to the background effects. Assuming that the Lorentz violation on the Earth is much larger than those on the interstellar scale, we automatically escape all the astrophysical constraints on Lorentz violation. For the BDLV from the effective field theory, we present a simple model and discuss the possible solutions to the theoretical challenges of the OPERA experiment such as the Bremsstrahlung effects for muon neutrinos and the pion decays. Also, we address the Lorentz violation constraints from the LEP and KamLAMD experiments. For the BDLV from the Type IIB string theory with D3-branes and D7-branes, we point out that the D3-branes are flavour blind, and all the SM particles are the conventional particles as in the traditional SM when they do not interact with the D3-branes. Thus, we not only can naturally avoid all the known phenomenological constraints on Lorentz violation, but also can naturally explain all the theoretical challenges. Interestingly, the energy dependent photon velocities may be tested at the experiments.Comment: RevTex4, 14 pages, minor corrections, references adde

    The Supersymmetric Standard Models with Decay and Stable Dark Matters

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    We propose two supersymmetric Standard Models (SMs) with decaying and stable dark matter (DM) particles. To explain the SM fermion masses and mixings and have a heavy decay DM particle S, we consider the Froggatt-Nielsen mechanism by introducing an anomalous U(1)_X gauge symmetry. Around the string scale, the U(1)_X gauge symmetry is broken down to a Z_2 symmetry under which S is odd while all the SM particles are even. S obtains a vacuum expectation value around the TeV scale, and then it can three-body decay dominantly to the second/third family of the SM leptons in Model I and to the first family of the SM leptons in Model II. Choosing a benchmark point in the constrained minimal supersymmetric SM with exact R parity, we show that the lightest neutralino DM is consistent with the CDMS II experiment. Considering S three-body decay and choosing suitable parameters, we show that the PAMELA and Fermi-LAT experiments and the PAMELA and ATIC experiments can be explained in Model I and Model II, respectively.Comment: RevTex4, 26 pages, 6 figures, references added, version to appear in EPJ
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