Christian Ewert, Amrit Sharma Poudel, Mouadh Ayache
et al.
Hash functions have become a key part of standard Post-quantum cryptography (PQC) schemes, especially Sha-3 and Shake, calling arXiv:submit/7045552 [cs.AR] 3 Dec 2025 for lightweight implementation. A fault-resilient design is always desirable to make the whole PQC system reliable. We, therefore, propose a) a unified hash engine supporting Sha-3 and Shake that follows a byte-wise in-place partitioning mechanism of the so-called Keccak state, and b) an according fault detection for Keccak state protection exploiting its cube structure by deploying two-dimensional parity checks. It outperforms the state-of-the-art (SoA) regarding area requirements at competitive register-level fault detection by achieving 100% detection of three and still near 100% of higher numbers of Keccak state faults. Unlike SoA solutions, the proposed unified hash engine covers all standard hash configurations. Moreover, the introduced multidimensional cross-parity check mechanism achieves a 3.7x improvement in area overhead, with an overall 4.5x smaller fault-resilient engine design as demonstrated in ASIC and FPGA implementations. Integrated into a RISC-V environment, the unified hash engine with the integrated fault-resilient mechanism introduced less than 8% area overhead. Our approach thus provides a robust and lightweight fault-detection solution for protecting hash functions deployed in resource-constrained PQC applications.
A. E. Mironov, D. L. Carroll, J. W. Zimmerman
et al.
Cs atomic lasers, operating on the D2 line and pumped by the photoassociation of Cs-rare gas thermal collision pairs, have been examined in mixtures of Cs vapor with Ar, Kr, or Xe. Photoexcitation of the B 2Σ+ − X 2Σ+ molecular transition (i.e., the blue satellite of the D2 transition) at 836.7 nm (Cs-Ar), 841.1 nm (Cs-Kr), or 842.7 nm (Cs-Xe) yields lasers at 852.1 nm whose characteristics (optical-to-optical conversion efficiencies, pump energy threshold, and temperature dependence) are a reflection of the structure of the B 2Σ+ interatomic potential associated with each Cs-rare gas pair. Output pulse energies above 100 μJ are obtained from the Cs-Ar complex in the 493–513 K interval because of the height of the B 2Σ+ barrier in the Franck-Condon region for the pump, a molecular parameter also responsible for the robust temperature stability of the laser. Slope efficiencies (with respect to absorbed pump energy) of 17%, 12%, and 27% have been measured for Cs-Ar, Cs-Kr, and Cs-Xe pairs at 473 K, 453 K, and 453 K, respectively. The data reported here firmly link the performance of a photodissociation laser with the structure of the intermediate diatomic complex.
Modern brand marketing communications are characterized by a high level of digitalization, which implies both the digitalization of promotion tools and digitalization of business processes. The increase in the degree of brands presence in digital environment gives grounds for scientific and practical reflection on the problems of “digital brand” development. Immersive technologies (virtual, augmented, mixed reality) are considered as forms of brand communication digitalization with target audiences. These technologies allow clients to “immerse” in another (virtual) world, to feel brand atmosphere. This paper focuses on the specifics of augmented reality technology in “brand - audience” communication, which fully reflects the philosophy of phygital marketing, where the customer's journey is associated with constant “shifts” from the physical world to digital world. Foreign experts designate AR-marketing as a separate area in the structure of marketing communications of a brand. The integration of physical promotion tools and augmented reality tools allows us to demonstrate the benefits of goods and services, promotes optimal choice, and forms necessary emotional connection of a brand with the representatives of its target audience. At the same time, a number of aspects of augmented reality technologies related to the audience interaction with branded augmented reality require specification; the nature of augmented reality influence on consumer decision-making; ways to involve consumers in communication based on augmented reality; changes in audience's attitude towards a brand as a result of interaction with branded augmented reality.
The mobilities of Cs+ ions in Ar, Kr, and Xe gases at 300 °K have been measured in a drift tube mass spectrometer for a wide range of values of the energy parameter E/N (the ratio of the electric field strength to the gas number density). Ion neutral interaction potentials have also been derived for each case (Cs+–Ar, Cs+–Kr, and Cs+–Xe). A kinetic theory appropriate to the nonthermalized ion motion is used to derive the mobilities from the potentials, and an iterative technique is used to modify the potentials to fit the experimental data. Various tests of the accuracy and uniqueness of the method indicate that this determination of the potentials gives errors in the potential parameters, e.g., well depth, well position, etc., which are less than about 10%.
The longitudinal electric field and the electron density and temperature have been measured in the positive column of low-pressure dc arc discharges in mixtures of cesium and argon at densities around 5×1018 and 5×1022 m−3, respectively. The measurements have been made with electrostatic probes and with a microwave interferometer. At a low discharge current cesium alone is ionized. When the discharge current is increased the cesium atom density is reduced by ionization and radial diffusion, and at a critical current a discontinuous transition to a state having a high electron temperature is observed. This discontinuity is explained as the result of a multivaluedness of the electric field as a function of the current density. Even at the present low degree of ionization the electron mobility is found to be strongly influenced by Coulomb collisions.
A model for the positive columns of dc low-pressure discharges in Cs–Ar mixtures, which includes radial depletion of Cs ground-state atoms and radiation trapping, is presented. The available experimental data for this discharge system were extended in such a way that comparison could be made between model calculations and experiments for a wide range of discharge currents and Cs vapor densities (0.2 × 1019−3.0 × 1019 m−3) and a reasonable agreement is obtained.
The radial and axial distributions of Cs ground-state (62S1/2) atoms in Cs–Ar low-pressure discharges are studied by absorption spectroscopy. The results show that there is appreciable Cs-atom depletion at the center of the discharge. Within experimental accuracy the Cs(62S1/2) concentration is found to be constant over the whole length of the positive column of the discharge.
Radial distributions of the 62P excited-state density of Cs in low-pressure Cs–Ar discharges have been measured by means of absorption from a continuum in the 876.1- and 917.2-nm lines of Cs. The variation of the excited-state densities with the discharge current has also been studied. The experimental data are compared with results of calculations based on a model of the positive column of the Cs–Ar discharge in which radiation trapping is taken into account.
The results of an experimental study of the absorption properties of Cs as present in Cs-Ar low-pressure discharges under various discharge conditions are presented. The total Cs concentration at zero discharge current was varied between 1.5 and 15×1012 cm−3. Absorption was measured in the 4555-Å and 8521-Å lines of Cs from which the stationary concentration of Cs (62S1/2) could be derived. Special attention was paid to determine the Cs concentration as the discharge changed from a low-burning voltage mode to a high-burning voltage mode. The pronounced variations of the discharge properties were found to be accompanied by rather drastic changes of the Cs concentration for which variations of a factor of ten or more were found.
The results of a spectroscopic determination of the concentration of excited Cs atoms in the 62P1/2 state as present in a low-pressure Cs-Ar discharge are presented. The concentrations are calculated from the measured absorption from a continuum source using a numerically calculated curve of growth for which the effects of hyperfine splitting are properly taken into account. At low current densities the excited state concentration varies linearly with the free electron concentration and the Cs ground state concentration as well. This result is used to estimate the effect of the trapping of the 62P1/2−62S1/2 resonance radiation on the lifetime of the 62P1/2 state.