3-Message Zero Knowledge Against Human Ignorance

The notion of Zero Knowledge has driven the field of cryptography since its conception over thirty years ago. It is well established that two-message zero-knowledge protocols for NP do not exist, and that four-message zero-knowledge arguments exist under the minimal assumption of one-way functions. Resolving the precise round complexity of zero-knowledge has been an outstanding open problem for far too long. In this work, we present a three-message zero-knowledge argument system with soundness against uniform polynomial-time cheating provers. The main component in our construction is the recent delegation protocol for RAM computations (Kalai and Paneth, TCC 2016B and Brakerski, Holmgren and Kalai, ePrint 2016). Concretely, we rely on a three-message variant of their protocol based on a key-less collision-resistant hash functions secure against uniform adversaries as well as other standard primitives. More generally, beyond uniform provers, our protocol provides a natural and meaningful security guarantee against real-world adversaries, which we formalize following Rogaway’s “human-ignorance” approach (VIETCRYPT 2006): in a nutshell, we give an explicit uniform reduction from any adversary breaking the soundness of our protocol to finding collisions in the underlying hash function.National Science Foundation (U.S.) (Award CNS-1350619)National Science Foundation (U.S.) (Award CNS-1413964

Dramatic robustness of a multiple delay dispersed interferometer to spectrograph errors: how mixing delays reduces or cancels wavelength drift

We describe demonstrations of remarkable robustness to instrumental noises by using a multiple delay externally dispersed interferometer (EDI) on stellar observations at the Hale telescope. Previous observatory EDI demonstrations used a single delay. The EDI (also called “TEDI”) boosted the 2,700 resolution of the native TripleSpec NIR spectrograph (950-2450 nm) by as much as 10x to 27,000, using 7 overlapping delays up to 3 cm. We observed superb rejection of fixed pattern noises due to bad pixels, since the fringing signal responds only to changes in multiple exposures synchronous to the applied delay dithering. Remarkably, we observed a ~20x reduction of reaction in the output spectrum to PSF shifts of the native spectrograph along the dispersion direction, using our standard processing. This allowed high resolution observations under conditions of severe and irregular PSF drift otherwise not possible without the interferometer. Furthermore, we recently discovered an improved method of weighting and mixing data between pairs of delays that can theoretically further reduce the net reaction to PSF drift to zero. We demonstrate a 350x reduction in reaction to a native PSF shift using a simple simulation. This technique could similarly reduce radial velocity noise for future EDI’s that use two delays overlapped in delay space (or a single delay overlapping the native peak). Finally, we show an extremely high dynamic range EDI measurement of our ThAr lamp compared to a literature ThAr spectrum, observing weak features (~0.001x height of nearest strong line) that occur between the major lines. Because of individuality of each reference lamp, accurate knowledge of its spectrum between the (unfortunately) sparse major lines is important for precision radial velocimetry

Chefs\u27 Perceptions of Zero Waste Cooking in Restaurants

The purpose of this study is to examine chefs’ perceptions and practices relative to current and potentially future efforts to decrease food waste. Through qualitative inquiry, this research aims to identify food waste reduction practices in Northwest Arkansas restaurants; chef’s perceptions of these practices and zero waste cooking; the impact these practices have on successfully implementing sustainability; and the biggest challenges in reducing food waste in restaurants. The results of this study will assist chefs and restaurant owners by providing guidance on practices easily utilized in restaurants currently. An interview protocol, with five sections, was conducted with ten chefs at different restaurants in Northwest Arkansas. The sections discussed food waste policy and tracking, training and communication, donation, food waste reduction practices, and perceptions of food waste. Chefs were asked to fill out a demographic questionnaire after the interviews were conducted. The results of this study indicated that Northwest Arkansas chefs are implementing multiple food waste reduction practices in their restaurants. Many chefs have begun a composting program, where they are educated on the importance of reducing food waste in landfills. The most common food waste reduction methods that chefs utilized were re-purposing ingredients, back-of-house training, portion size control, donating, and composting. Training was an important aspect in successfully implementing food waste, with chefs stating that chefs must be passionate about reducing food waste for the process to be successful. Cooperation and lack of knowledge emerged as the biggest challenges in reducing food waste. The results of this study indicated that chefs tended to be confused on what constituted as zero waste cooking, suggesting that a more universal definition be created. It is hoped the results from this study will lead to further research in food waste reduction practices and zero waste cooking, resulting in an awareness of the magnitude food waste has on the world. Results from this study can be used as a catalyst for conducting follow-up research on food waste reduction practices in other cities, allowing a more comprehensive look at food waste across the country

Field-effect mobility extraction in nanowire field-effect transistors by combination of transfer characteristics and random telegraph noise measurements

A technique based on the combined measurements of random telegraph-signal noise amplitude and drain current vs. gate voltage characteristics is proposed to extract the channel mobility in inversion-mode and accumulation-mode nanowire transistors. This method does not require the preliminary knowledge of the gate oxide capacitance or that of the channel width. The method accounts for the presence of parasitic source and drain resistance effect. It has been used to extract the zero-field mobility and the field mobility reduction factor in inversion-mode and junctionless transistors operating in accumulation mode. (C) 2011 American Institute of Physics. (doi:10.1063/1.3626038

Local state space reduction of multi-scale systems

Modelling reaction kinetics in a homogeneous medium usually leads to stiff systems of ordinary differential equations the dimension of which can be large. A well-known approach to reduce the dimension of such systems is the quasi-steady state assumption (QSSA): the derivative of fast variables is assumed to be zero. This procedure requires some knowledge of the underlying chemistry, moreover the corresponding differential system must be explicitly given. In this paper we shall describe and justify a procedure for a local reduction of the dimension of state space which does not require chemical insight as well as an explicit knowledge of the system in a singularly perturbed form. The mathematical justification is based on the theory of invariant manifolds