94 research outputs found

    Dynamic Security-aware Routing for Zone-based data Protection in Multi-Processor System-on-Chips

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    In this work, we propose a NoC which enforces the encapsulation of sensitive traffic inside the asymmetrical security zones while using minimal and non-minimal paths. The NoC routes guarantee that the sensitive traffic is communicated only through the trusted nodes which belong to the security zone. As the shape of the zones may change during operation, the sensitive traffic must be routed through low-risk paths. We test our proposal and we show that our solution can be an efficient and scalable alternative for enforce the data protection inside the MPSoC

    Self-induced decoherence in dense neutrino gases

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    Dense neutrino gases exhibit collective oscillations where "self-maintained coherence" is a characteristic feature, i.e., neutrinos of different energies oscillate with the same frequency. In a non-isotropic gas, however, the flux term of the neutrino-neutrino interaction has the opposite effect of causing kinematical decoherence of neutrinos propagating in different directions, an effect that is at the origin of the "multi-angle behavior" of neutrinos streaming off a supernova core. We cast the equations of motion in a form where the role of the flux term is manifest. We study in detail the symmetric case of equal neutrino and antineutrino densities where the evolution consists of collective pair conversions ("bipolar oscillations"). A gas of this sort is unstable in that an infinitesimal anisotropy is enough to trigger a run-away towards flavor equipartition. The "self-maintained coherence" of a perfectly isotropic gas gives way to "self-induced decoherence."Comment: Revtex, 16 pages, 12 figure

    Supernova Neutrino Opacity from Nucleon-Nucleon Bremsstrahlung and Related Processes

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    Elastic scattering on nucleons, \nu N -> N \nu, is the dominant supernova (SN) opacity source for \mu and \tau neutrinos. The dominant energy- and number-changing processes were thought to be \nu e^- -> e^- \nu and \nu\bar \nu e^+ e^- until Suzuki (1993) showed that the bremsstrahlung process \nu\bar \nu NN NN was actually more important. We find that for energy exchange, the related ``inelastic scattering process'' \nu NN NN \nu is even more effective by about a factor of 10. A simple estimate implies that the \nu_\mu and \nu_\tau spectra emitted during the Kelvin-Helmholtz cooling phase are much closer to that of \nu\bar_e than had been thought previously. To facilitate a numerical study of the spectra formation we derive a scattering kernel which governs both bremsstrahlung and inelastic scattering and give an analytic approximation formula. We consider only neutron-neutron interactions, we use a one-pion exchange potential in Born approximation, nonrelativistic neutrons, and the long-wavelength limit, simplifications which appear justified for the surface layers of a SN core. We include the pion mass in the potential and we allow for an arbitrary degree of neutron degeneracy. Our treatment does not include the neutron-proton process and does not include nucleon-nucleon correlations. Our perturbative approach applies only to the SN surface layers, i.e. to densities below about 10^{14} g cm^{-3}.Comment: 36 pages, LaTeX, 6 postscript figs included, matches version accepted for publication in Astrophysical Journa

    A Secure Dual-MCU Architecture for Robust Communication of IIoT Devices

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    The Industrial Internet of Things (IIoT) has already become a part of our everyday life be it water supply, smart grid, or production, IIoT is everywhere. For example, factory operators want to know the current state of the production line. These new demands for data acquisition in modern plants require industrial components to be able to communicate. Nowadays, network communication in Industrial Control Systems (ICSs) is often implemented via an IP-based protocol. This intercommunication also brings a larger attack surface for hackers. If an IIoT device is influenced by attackers, the physical process could be affected. For example, a high network load could cause a high Central Processing Unit (CPU) load and influence the reaction time on the physical control side. In this paper, we introduce a dual Microcontroller Unit (MCU) setup to ensure a resilient controlling for IIoT devices like Programmable Logic Controllers (PLCs). We introduce a possible solution for the demand of secure architectures in the IIoT. Moreover, we provide a Proof of Concept (PoC) implementation with a benchmark and a comparison with a standard PLC

    Defeating microprobing attacks using a resource efficient detection circuit

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    Microprobing is an attack technique against integrated circuits implementing security functions, such as OTP tokens or smartcards. It allows intercepting secrets from onchip wires as well as injecting faults for other attacks. While the necessity to etch open chip packages and to remove the passivation layer makes microprobing appear expensive, it was shown that a successful attack can be run with equipment worth a few thousand euros. On the protector’s side, however, appropriate countermeasures such as active shields, redundancy of core components, or analog detection circuits containing large capacitors, are still expensive. We present a resource efficient microbing detection circuit that we call Low Area Probing Detector (LAPD). It measures minimal timing differences between on-chip wires caused by the capacitive load of microprobes. Simulations show that it can detect up-todate probes with capacitances as low as 10 fF. As a novelty, the LAPD is merely based on digital components and does not require analog circuitry, which reduces the required area and process steps compared to previous approaches.Postprint (author’s final draft

    TOFU - Toggle Count Analysis made simple

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    Protection against physical attacks is a major requirement for cryptographic implementations running on devices which are accessible to an attacker. Side-channel attacks are the most common types of physical attacks, the most frequent side-channel is the device\u27s power consumption. In this work we propose a novel open-source tool called TOFU which synthesizes VCD simulation traces into power traces, with adjustable leakage models. Additionally, we propose a workflow which is only based on open-source tools. The functionality of TOFU and the proposed workflow was verified by a CPA of a AES hardware implementation. We also provide numbers for the required running time of TOFU for a trace synthesis with respect to the according VCD file size. Furthermore, we provide TOFU\u27s source code
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