CryptoMask : Privacy-preserving Face Recognition

Face recognition is a widely-used technique for identification or verification, where a verifier checks whether a face image matches anyone stored in a database. However, in scenarios where the database is held by a third party, such as a cloud server, both parties are concerned about data privacy. To address this concern, we propose CryptoMask, a privacy-preserving face recognition system that employs homomorphic encryption (HE) and secure multi-party computation (MPC). We design a new encoding strategy that leverages HE properties to reduce communication costs and enable efficient similarity checks between face images, without expensive homomorphic rotation. Additionally, CryptoMask leaks less information than existing state-of-the-art approaches. CryptoMask only reveals whether there is an image matching the query or not, whereas existing approaches additionally leak sensitive intermediate distance information. We conduct extensive experiments that demonstrate CryptoMask's superior performance in terms of computation and communication. For a database with 100 million 512-dimensional face vectors, CryptoMask offers ${\thicksim}5 \times$ and ${\thicksim}144 \times$ speed-ups in terms of computation and communication, respectively.Comment: 18 pages,3 figures, accepted by ICICS202

Secret-Shared Shuffle with Malicious Security

A secret-shared shuffle (SSS) protocol permutes a secret-shared vector using a random secret permutation. It has found numerous applications, however, it is also an expensive operation and often a performance bottleneck. Chase et al. (Asiacrypt\u2720) recently proposed a highly efficient semi-honest two-party SSS protocol known as the CGP protocol. It utilizes purposely designed pseudorandom correlations that facilitate a communication-efficient online shuffle phase. That said, semi-honest security is insufficient in many real-world application scenarios since shuffle is usually used for highly sensitive applications. Considering this, recent works (CANS\u2721, NDSS\u2722) attempted to enhance the CGP protocol with malicious security over authenticated secret sharings. However, we find that these attempts are flawed, and malicious adversaries can still learn private information via malicious deviations. This is demonstrated with concrete attacks proposed in this paper. Then the question is how to fill the gap and design a maliciously secure CGP shuffle protocol. We answer this question by introducing a set of lightweight correlation checks and a leakage reduction mechanism. Then we apply our techniques with authenticated secret sharings to achieve malicious security. Notably, our protocol, while increasing security, is also efficient. In the two-party setting, experiment results show that our maliciously secure protocol introduces an acceptable overhead compared to its semi-honest version and is more efficient than the state-of-the-art maliciously secure SSS protocol from the MP-SPDZ library

Superconductivity in a new layered cobalt oxychalcogenide Na6_{6}Co3_{3}Se6_{6}O3_{3} with a 3d5d^{5} triangular lattice

Unconventional superconductivity in bulk materials under ambient pressure is extremely rare among the 3$d$ transition-metal compounds outside the layered cuprates and iron-based family. It is predominantly linked to highly anisotropic electronic properties and quasi-two-dimensional (2D) Fermi surfaces. To date, the only known example of the Co-based exotic superconductor was the hydrated layered cobaltate, Na$_{x}$CoO$_{2}\cdot$ yH$_{2}$O, and its superconductivity is realized in the vicinity of a spin-1/2 Mott state. However, the nature of the superconductivity in these materials is still an active subject of debate, and therefore, finding new class of superconductors will help unravel the mysteries of their unconventional superconductivity. Here we report the discovery of unconventional superconductivity at $\sim$ 6.3 K in our newly synthesized layered compound Na$_{6}$Co$_{3}$Se$_{6}$O$_{3}$, in which the edge-shared CoSe$_{6}$ octahedra form [CoSe$_{2}$] layers with a perfect triangular lattice of Co ions. It is the first 3$d$ transition-metal oxychalcogenide superconductor with distinct structural and chemical characteristics. Despite its relatively low $T_{c}$, material exhibits extremely high superconducting upper critical fields, $\mu_{0}H_{c2}(0)$, which far exceeds the Pauli paramagnetic limit by a factor of 3 - 4. First-principles calculations show that Na$_{6}$Co$_{3}$Se$_{6}$O$_{3}$ is a rare example of negative charge transfer superconductor. This new cobalt oxychalcogenide with a geometrical frustration among Co spins, shows great potential as a highly appealing candidate for the realization of high-$T_{c}$ and/or unconventional superconductivity beyond the well-established Cu- and Fe-based superconductor families, and opened a new field in physics and chemistry of low-dimensional superconductors

Stable structure and effects of the substrate Ti pre-treatment on the epitaxial growth of SrTiO

The structural and electronic properties of Ti in the SrTiO3/GaAs(001) interface are studied using the density functional theory. In all the structures examined, the formation energy of Ti on GaAs(001) decreases with decreasing Ti coverage. Sr or Ti adsorption atoms at the fourfold hollow sites with $1/4$ monolayer coverage on the GaAs(001) surface are the most energetically favorable. And, Sr atoms are adsorbed on the surface and Ti atoms are adsorbed below the surface, which is in agreement with the results in experiments. Ga vacancy can form spontaneously for the Ga-terminated (001) GaAs surface. Ti atoms may substitute Ga atoms, or accumulate at the voids inside the GaAs film during growth. Not only heterostructures with a regular perovskite but also heterostructures with Ti-insertion and Ti-substitution defects are investigated. The growth of the SrO-layer on the Ga-terminated surface is more stable, although all kinds of sequence among the SrO-, TiO2-layer on a Ga-, As-terminated surface are possible. Substituting Ti for Ga enhances the stability of SrTiO3 on Ga-terminated (001) GaAs. The electronic structures and properties of the heterointerfaces SrTiO3/GaAs(001) are presented, and a metallic behavior is predicted at the interface of SrTiO3/GaAs with/without Ti-insertion

First-principles study of Sr adsorption on InN (0001)

Structures of Sr adsorbed on InN (0001) surfaces are theoretically investigated by first-principles calculations. The adsorption energies of Sr on InN (0001) decrease with decreasing Sr coverage. An InN (0001)-(2×2) surface structure covered by a 1/4 monolayer of Sr at the T4 sites may be the most energetically favourable. Sr atoms may substitute indium atoms, or accumulate at the voids inside InN films. The interstitial Sr defects may act as a potential source of compensation for the p-type behaviour of Sr-doped InN at the surface

Airborne Position and Orientation System for Aerial Remote Sensing

The airborne Position Orientation System (POS) can accurately measure space-time reference information and plays a vital role in aerial remote sensing system. It may be applied in a direct georeference system for optical camera and a motion imaging system for Synthetic Aperture Radar (SAR), which further advances efficiency and quality of imaging sensors. In this paper, the operation principle and components of airborne POS are introduced. Some key technologies of airborne POS are summarized. They include the error calibration and compensation, initial alignment, lever arm error modeling, time synchronization, and integrated estimation method. A high precision airborne POS has been developed and applied to a variety of aerial remote sensing systems

Blood cells and hematological parameters of the mountain dragon, Diploderma micangshanensis (Squamata: Lacertilia: Agamidae)

Hematological characteristics reflect the health status of animals and their physiological adaptation to the environment. However, few studies focused on the species of Diploderma. In this study, the blood cells and the hematological parameters of Diploderma micangshanensis, a species endemic to China, were examined based on 48 healthy adult (32 males and 16 females). The blood cells and hematological parameters of D. micangshanensis were similar to those of other lizard species. Although the values of erythrocyte morphometric characters and hematological parameters varied between males and females, the differences were only significant in the case of the hematocrit and erythrocyte size, which may allow for higher oxygen availability in males. Hemoglobin, mean corpuscular hemoglobin concentration, and mean corpuscle volume were strongly affected by the snout-vent length and/or body mass, which reflect the physiological adaptation to the oxygen requirement of different individuals. This is the first report of hematological data from a species of Diploderma, and the results will provide data for research on the adaptive evolution and health assessment in this species and other congeners

Mitochondrial genome of Diploderma micangshanense and its implications for phylogeny of the genus Diploderma

The lizard Diploderma micangshanense, which belongs to the family Agamidae is endemic to China. Here, we determined the complete mitogenome of D. micangshanense using an Illumina Hiseq X Ten sequencer. This mitogenome’s structure is a typical circular molecule of 16,467 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a control region. The overall base composition of D. micangshanensis is 34.1% A, 23.64% T, 13.62% C, and 28.64% G with a slight AT bias of 57.74%. Most mitochondrial genes except ND6 and seven tRNAs were encoded on the heavy strand. Notably, the trnP gene was encoded on the heavy strand instead of its typical light strand position, providing an example of gene inversion in vertebrate mitogenomes. Phylogenetic analysis indicated that D. micangshanensis had a close relationship with D. zhaoermii