This paper presents new speed records for 128-bit secure elliptic-curve Diffie–Hellman key-exchange software on three different popular microcontroller architectures. We consider a 255-bit curve proposed by Bernstein known as Curve25519, which has also been adopted the IETF. optimize X25519 protocol in 2006 AVR ATmega 8-bit microcontrollers, MSP430X 16-bit and ARM Cortex-M0 32-bit microcontrollers. Our takes only 13,900,397 cycles computation of shared secret, is first to perform this less...

Increasingly connectivity becomes integrated in products and devices that previously operated a stand-alone setting. This observation holds for many consumer applications the so-called "Internet of Things" (IoT) as well corresponding industry (IIoT), such industrial process sensors. Often only practicable means authentication human users is password. The security password-based schemes frequently forms weakest point infrastructure. In this paper we first explain why tailored protocol...

Four-wave-mixing signals from excitons under linear-circular polarized excitation exhibit an elliptical polarization, depending on both the pulse delay and spectral position. Besides resonances corresponding to exciton-biexciton transitions, a breakup of exciton line is found reflecting influence correlations four-point level. An analysis accounting for density, bound biexciton, exciton-exciton scattering continuum reveals that these features are not due antibound two-exciton state. Instead,...

Increasingly connectivity becomes integrated in products and devices that previously operated a stand-alone setting. This observation holds for many consumer applications the so-called Internet of Things (IoT) as well corresponding industry (IIoT), such industrial process sensors. Often only practicable means authentication human users is password. The security password-based schemes frequently forms weakest point infrastructure. In this paper we first explain why tailored protocol designed...

The detection of terahertz photons by using silicon-based devices enabled visible is one the fundamental ideas quantum optics. Here, we present a classical principle optical upconversion to near-infrared spectral range in picosecond pulse regime, which finally enables with conventional sCMOS camera. By superimposing and pump pulses periodically poled lithium-niobate crystal, at 0.87 THz are converted wavelengths close central wavelength 776 nm. A tunable delay between helps overlap...

The memory structure induced by coherent transitions to the exciton-exciton scattering continuum is shown have significant influence on spectrally resolved four-wave-mixing signals even under selective excitation of 1s excitons. Comparisons between experiments and calculations that account nonperturbatively for these quantum kinetic Coulomb correlations demonstrate large compensations mean-field contributions two-pair continuum. Experiments with different polarizations laser pulses show are...

The polarization state of the diffracted beam in degenerate four-wave mixing is experimentally and theoretically investigated, resolved time as well frequency domain. use thin ZnSe quantum wells having large (bi)exciton binding energies makes it possible to restrict optical excitation by broadband 110 fs pulses quasi-two-dimensional heavy-hole excitons biexcitons only. Despite these most simple experimental conditions, an extremely complex dynamics observed when one circularly linearly...

A systematic analysis of excitonic and biexcitonic contributions to four-wave mixing in dependence on the polarization state intensity exciting beams is presented for ZnSe/Zn1—xMgxSySe1—iiy quantum wells. The relative signals excitons biexcitons different configurations are discussed terms a microscopic density matrix model revealing excellent correspondence complex experimental data. In which do not allow third-order contribution biexciton zero angular momentum higher-order correlations...

It is shown that lower bounds for the effective memory time induced by two-pair correlations can be estimated monitoring changes of shape excitonic four-wave-mixing spectra. Experimentally we demonstrate a at least 540 fs ZnSe single quantum well. Microscopic calculations reveal this bound not sharp. Interactions retarded more than 800 are to influence dynamics, reflecting presence long tail in kernel.

Unlike in established methods, the phase of an optical pulse is calculated from a single time transient combination with spectrum its polarization state: For dynamically changing elliptical polarizations vectorial nature electromagnetic radiation results two independent constraints that uniquely determine chirp and spectral phase. The practical feasibility method demonstrated, four-wave-mixing signal semiconductor quantum well energy only 0.5 fJ determined, accuracy setup analyzed by...

This paper describes an ECC implementation computing the X25519 keyexchange protocol on Arm Cortex-M4 microcontroller. For providing protections against various side-channel and fault attacks we first review known countermeasures, then provide software implementations that come with extensive mitigations, finally present a preliminary evaluation. To our best knowledge, this is public claiming affordable protection multiple classes of are motivated by distinct real-world application...

The optical phase of four-wave-mixing (FWM) signals from a ZnSe single quantum well is analyzed experimentally and theoretically. focus on excitation conditions where the polarization state emitted light dynamically changing rather than being fixed by selection rules, case known to be sensitive high-order Coulomb correlations. measured using an iterative procedure taking as input FWM with real-time resolution frequency regime data. results are compared microscopical density-matrix...

Terahertz spectroscopy allows for identifying different isomers of materials, drug discrimination as well detecting hazardous substances. As many dielectric materials used packaging are transparent in the terahertz spectral range, substances might even be identified if packaged. Despite these useful applications, suffers from still technically demanding detection radiation. Thus, either coherent time-domain-spectroscopy schemes employing ultrafast pulsed lasers or continuous-wave with...

Summary form only given. Recently, four-wave-mixing (FWM) experiments on semiconductors have been extended by time-resolved analysis of the polarization state diffracted pulses. It was found that seemingly unpolarized fraction signal observed in time-integrated data is caused averaging over a pulse having perfect which, however, changes time. Since certain configurations occurrence time dependent due to processes higher than third order driving fields, measurement its intensity dependence...