INTERFACIAL TENSION OF 3He - 4He LIQUID MIXTURES UNDER PRESSURE

La tension superficielle à l'interface entre les phases liquides séparées de mélanges 3He-4He a été étudiée en fonction de la température de 0,3 K à 0,7 K, et de la pression entre la pression de vapeur saturante et vingt atmosphères. La hauteur du ménisque mesurée depuis sa base, a été déterminée par une technique d'interferometrie holographique.The interfacial surface tension of phase separated 3He-4He liquid mixtures has been studied as a function of temperature from 0.3 K to 0.7 K and of pressure from saturated vapor pressure to twenty atmospheres. The technique of real time holographic interferometry has been used in determining the height of the interfacial meniscus as measured from its bottom

SIMPL systems as a keyless cryptographic and security primitive

We discuss a recent cryptographic primitive termed SIMPL system, where the acronym stands for SIMulation Possible, but Laborious. Like Physical Unclonable Functions (PUFs), SIMPL systems are disordered, unclonable physical systems with many possible inputs and a complex input-output behavior. Contrary to PUFs, however, each SIMPL system comes with a publicly known, individual numeric description that allows its slow simulation and output prediction. While everyone can determine a SIMPL system's output slowly by simulation, only its actual holder can determine the output fast by physical measurement. This added functionality allows new public key like protocols and applications. But SIMPLs have a second, perhaps more striking advantage: No secret information is, or needs to be, contained in SIMPL systems in order to enable cryptographic security. Neither in the form of a standard digital key, nor as secret information hidden in the random, analog features of some hardwar e, as it is the case for PUFs. The security of SIMPL systems instead rests on (i) an assumption regarding their physical unclonability, and (ii) a computational assumption on the complexity of simulating their output. This provides SIMPL systems with a natural immunity against any key extraction attacks, including malware, side channel, invasive, and modeling attempts. In this manuscript, we give a comprehensive discussion of SIMPLs as a cryptographic and security primitive. Special emphasis is placed on the different cryptographic protocols that are enabled by this new tool