Embedded LUKS (E-LUKS): A Hardware Solution to IoT Security

The Internet of Things (IoT) security is one of the most important issues developers have to face. Data tampering must be prevented in IoT devices and some or all of the confidentiality, integrity, and authenticity of sensible data files must be assured in most practical IoT applications, especially when data are stored in removable devices such as microSD cards, which is very common. Software solutions are usually applied, but their effectiveness is limited due to the reduced resources available in IoT systems. This paper introduces a hardware-based security framework for IoT devices (Embedded LUKS) similar to the Linux Unified Key Setup (LUKS) solution used in Linux systems to encrypt data partitions. Embedded LUKS (E-LUKS) extends the LUKS capabilities by adding integrity and authentication methods, in addition to the confidentiality already provided by LUKS. E-LUKS uses state-of-the-art encryption and hash algorithms such as PRESENT and SPONGENT. Both are recognized as adequate solutions for IoT devices being PRESENT incorporated in the ISO/IEC 29192-2:2019 for lightweight block ciphers. E-LUKS has been implemented in modern XC7Z020 FPGA chips, resulting in a smaller hardware footprint compared to previous LUKS hardware implementations, a footprint of about a 10% of these LUKS implementations, making E-LUKS a great alternative to provide Full Disk Encryption (FDE) alongside authentication to a wide range of IoT devices.

In the Trenches of the Solar-stellar Connection. V. High-resolution Ultraviolet and X-Ray Observations of Sun-like Stars: The Curious Case of Procyon

A joint X-ray (0.2–2 keV) and ultraviolet (1150–3000 Å) time-domain study has been carried out on three nearby bright late-type stars, bracketing the Sun in properties. Alpha Cen A (HD 128620: G2 V) is a near twin to the Sun, although slightly more massive and luminous, slightly metal-rich, but older. Alpha Cen B (HD 128621: K1 V) is cooler than the Sun, somewhat less massive and lower in luminosity. Procyon (HD 61421: F5 IV–V) is hotter, more massive and more luminous than the Sun, half the age, but more evolved. Stellar observations were from Chandra X-ray Observatory and Hubble Space Telescope (HST). The Sun provided a benchmark through high-energy spectral scans from solar irradiance satellites and novel high-dispersion full-disk profiles of key UV species—Mg ii, C ii, and Si iv—from the Interface Region Imaging Spectrograph. Procyon’s flux history was strikingly constant at all wavelengths, in contrast to the other three cycling-dynamo stars. Procyon also displays a strong subcoronal (T ∼ 1 × 105 K) emission excess, relative to chromospheric Mg ii (T ≲ 104 K), although its X-rays (T ∼ 2 MK) appear to be more normal. At the same time, the odd sub-Gaussian shapes, and redshifts, of the subgiant’s “hot lines” (such as Si iv and C iv) are remarkably similar to the solar counterparts (and α Cen AB). This suggests a Sun-like origin, namely a supergranulation network supplied by magnetic flux from a noncycling “local dynamo.”

Origin of the Solar Rotation Harmonics Seen in the EUV and UV Irradiance

Long-term periodicities in the solar irradiance are often observed with periods proportional to the solar rotational period of 27 days. These periods are linked either to some internal mechanism in the Sun or said to be higher harmonics of the rotation without further discussion of their origin. In this article, the origin of the peaks in periodicities seen in the solar extreme ultraviolet (EUV) and ultraviolet (UV) irradiance around the 7, 9, and 14 days periods is discussed. Maps of the active regions and coronal holes are produced from six images per day using the Spatial Possibilistic Clustering Algorithm (SPoCA), a segmentation algorithm. Spectral irradiance at coronal, transition-region/chromospheric, and photospheric levels are extracted for each feature as well as for the full disk by applying the maps to full-disk images (at 19.3, 30.4, and 170 nm sampling in the corona/hot flare plasma, the chromosphere/transition region, and the photosphere, respectively) from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) from January 2011 to December 2018. The peaks in periodicities at 7, 9, and 14 days as well as the solar rotation around 27 days can be seen in almost all of the solar irradiance time series. The segmentation also provided time series of the active regions and coronal holes visible area (i.e. in the area observed in the AIA images, not corrected for the line-of-sight effect with respect to the solar surface), which also show similar peaks in periodicities, indicating that the periodicities are due to the change in area of the features on the solar disk rather than to their absolute irradiance. A simple model was created to reproduce the power spectral density of the area covered by active regions also showing the same peaks in periodicities. Segmentation of solar images allows us to determine that the peaks in periodicities seen in solar EUV/UV irradiance from a few days to a month are due to the change in area of the solar features, in particular, active regions, as they are the main contributors to the total full-disk irradiance variability. The higher harmonics of the solar rotation are caused by the clipping of the area signal as the regions rotate behind the solar limb.

The Emirates Exploration Imager (EXI) Instrument on the Emirates Mars Mission (EMM) Hope Mission

The Emirates Exploration Imager (EXI) on-board the Emirates Mars Mission (EMM) offers both regional and global imaging capabilities for studies of the Martian atmosphere. EXI is a framing camera with a field-of-view (FOV) that will easily capture the martian disk at the EMM science orbit periapsis. EXI provides 6 bandpasses nominally centered on 220, 260, 320, 437, 546, 635 nm using two telescopes (ultraviolet (UV) and visible(VIS)) with separate optics and detectors. Images of the full-disk are acquired with a resolution of 2–4 km per pixel, where the variation is driven by periapsis and apoapsis points of the orbit, respectively. By combining multiple observations within an orbit with planetary rotation, EXI is able to provide diurnal sampling over most of the planet on the scale of 10 days. As a result, the EXI dataset allows for the delineation of diurnal and seasonal timescales in the behavior of atmospheric constituents such as water ice clouds and ozone.This combination of temporal and spatial distinguishes EXI from somewhat similar imaging systems, including the Mars Color Imager (MARCI) onboard the Mars Reconnaissance Orbiter (MRO) (Malin et al. in Icarus 194(2):501–512, 2008) and the various cameras on-board the Hubble Space Telescope (HST; e.g., James et al. in J. Geophys. Res. 101(E8):18,883–18,890, 1996; Wolff et al. in J. Geophys. Res. 104(E4):9027–9042, 1999). The former, which has comparable spatial and spectral coverage, possesses a limited local time view (e.g., mid-afternoon). The latter, which provides full-disk imaging, has limited spatial resolution through most of the Martian year and is only able to provide (at most) a few observations per year given its role as a dedicated, queue-based astrophysical observatory. In addition to these unique attributes of the EXI observations, the similarities with other missions allows for the leveraging of both past and concurrent observations. For example, with MARCI, one can build on the ∼6 Mars years of daily global UV images as well as those taken concurrently with EXI.

INTERPRETATION OF OPTICAL AND IR LIGHT CURVES FOR TRANSITIONAL DISK CANDIDATES IN NGC 2264 USING THE EXTINCTED STELLAR RADIATION AND THE EMISSION OF OPTICALLY THIN DUST INSIDE THE HOLE

In the stellar forming region NGC 2264 there are objects catalogued as hosting a transitional disk according to spectrum modeling. Four members of this set have optical and infrared light curves coming from the CoRoT and Spitzer telescopes. In this work, we try to simultaneously explain the light curves using the extinction of the stellar radiation and the emission of the dust inside the hole of a transitional disk. For the object Mon-296, we were successful. However, for Mon-314, and Mon-433 our evidence suggests that they host a pre-transitional disk. For Mon-1308 a new spectrum fitting using the 3D radiative transfer code Hyperion allows us to conclude that this object hosts a full disk instead of a transitional disk. This is in accord to previous work on Mon-1308 and with the fact that we cannot find a fit for the light curves using only the contribution of the dust inside the hole of a transitional disk.