Cellular Automata in Cryptographic Random Generators

Cryptographic schemes using one-dimensional, three-neighbor cellular automata as a primitive have been put forth since at least 1985. Early results showed good statistical pseudorandomness, and the simplicity of their construction made them a natural candidate for use in cryptographic applications. Since those early days of cellular automata, research in the field of cryptography has developed a set of tools which allow designers to prove a particular scheme to be as hard as solving an instance of a well-studied problem, suggesting a level of security for the scheme. However, little or no literature is available on whether these cellular automata can be proved secure under even generous assumptions. In fact, much of the literature falls short of providing complete, testable schemes to allow such an analysis. In this thesis, we first examine the suitability of cellular automata as a primitive for building cryptographic primitives. In this report, we focus on pseudorandom bit generation and noninvertibility, the behavioral heart of cryptography. In particular, we focus on cyclic linear and non-linear automata in some of the common configurations to be found in the literature. We examine known attacks against these constructions and, in some cases, improve the results. Finding little evidence of provable security, we then examine whether the desirable properties of cellular automata (i.e. highly parallel, simple construction) can be maintained as the automata are enhanced to provide a foundation for such proofs. This investigation leads us to a new construction of a finite state cellular automaton (FSCA) which is NP-Hard to invert. Finally, we introduce the Chasm pseudorandom generator family built on this construction and provide some initial experimental results using the NIST test suite

Ecosystem effects of ocean acidification

I am investigating areas of the seabed that are already acidified by carbon dioxide, so that we can see which organisms thrive and which are most vulnerable. To do this I am investigating underwater volcanoes where carbon dioxide bubbles up like a Jacuzzi, acidifying large areas of the seabed for 100s of years. The natural gradients of carbon dioxide are like a time machine, showing which organisms can survive and what coastal habitats might look like in the coming years. But a major criticism has been that all my work was focused on one volcanic vent site off Ischia Island near Vesuvius; so how is this relevant to the people who grow shellfish in the NE Atlantic or those that show tourists the Great Barrier Reef? For the past year my group has been repeating the Ischia experiments at other volcanic vents in Europe, Baja California and Papua New Guinea. What concerns me most is that as the carbon dioxide levels increase to those we expect to see in our life-times this causes a dramatic loss of marine biodiversity, both in temperate and in tropical systems. Key groups, like sea urchins and coralline algae, cannot survive as the water becomes corrosive, and fish avoid the high carbon dioxide areas when they lay their eggs. Some organisms are able to adapt to the effects of long-term acidification – some can calcify even faster at high carbon dioxide levels - but the vents mainly benefit non-calcified organisms. Invasive species of algae and stinging jellyfish do especially well. Some species have an outer layer of protective tissue that allows them to tolerate acidified seawater, such as Porites corals in the tropics and Mytilus mussels in temperate areas. But these carbon dioxide tolerant organisms can only survive if they are not stressed by other factors. We have found that the combination of acidification and rising temperatures kills-off corals and shellfish and that increasing carbon dioxide reduces biodiversity across-the-board, from simple organisms (such as bacteria and microalgae), to flora (like seaweeds and seagrasses), and fauna (such as corals and molluscs). I hope that information from these naturally acidified areas will be used to strengthen marine conservation efforts, as unstressed systems are more resilient than stressed ones.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Global existence for a coupled wave system related to the Strauss conjecture

A coupled system of semilinear wave equations is considered, and a small data global existence result related to the Strauss conjecture is proved. Previous results have shown that one of the powers may be reduced below the critical power for the Strauss conjecture provided the other power sufficiently exceeds such. The stability of such results under asymptotically flat perturbations of the space-time where an integrated local energy decay estimate is available is established.Comment: 12 page

Letter from the Editors

[Excerpt] The Editorial Team is proud to release this 2016 14th Annual Volume of the Cornell Real Estate Review. This year’s issue explores a wide range of topics, including the deployment of new technologies in multifamily properties, the effects of autonomous vehicles on real estate, and the continued ramifications of the housing crisis through the legal tactics of certain mortgage lenders. Also included, a recent repositioning project– the unique turnaround of a former casino hotel property in Reno, Nevada. Furthermore, this release includes a discussion of value-added multifamily investment strategy, an analysis of the impact of rapid transit on the residential market in Hudson County, New Jersey, and a summary of federal affordable housing incentive programs in the United States. This year’s Pathways features an interview with Toll Brothers Division President Karl Mistry (Baker ’04), and the Baker Viewpoint piece explores the concept of curtailment mortgages

Metamorphic, Autonomous Symmetries

Unified signed models have led to many intuitive advances, including courseware and lambda calculus. In fact, few developers would disagree with the construction of the UNIVAC computer, which embodies the unfortunate principles of cryptoanalysis. We examine how DHCP can be applied to the evaluation of vacuum tubes

Generating Software for Well-Understood Domains

Current software development is often quite code-centric and aimed at short-term deliverables, due to various contextual forces (such as the need for new revenue streams from many individual buyers). We're interested in software where different forces drive the development. \textbf{Well understood domains} and \textbf{long-lived software} provide one such context. A crucial observation is that software artifacts that are currently handwritten contain considerable duplication. By using domain-specific languages and generative techniques, we can capture the contents of many of the artifacts of such software. Assuming an appropriate codification of domain knowledge, we find that the resulting de-duplicated sources are shorter and closer to the domain. Our prototype, Drasil, indicates improvements to traceability and change management. We're also hopeful that this could lead to long-term productivity improvements for software where these forces are at play.Comment: 12 pages, paper accepted at EVCS 202

Chapter Threats to Ultraoligotrophic Marine Ecosystems

Applied optic

Using productivity and susceptibility indices to assess the vulnerability of United States fish stocks to overfishing

Assessing the vulnerability of stocks to fishing practices in U.S. federal waters was recently highlighted by the National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration, as an important factor to consider when 1) identifying stocks that should be managed and protected under a fishery management plan; 2) grouping data-poor stocks into relevant management complexes; and 3) developing precautionary harvest control rules. To assist the regional fishery management councils in determining vulnerability, NMFS elected to use a modified version of a productivity and susceptibility analysis (PSA) because it can be based on qualitative data, has a history of use in other fisheries, and is recommended by several organizations as a reasonable approach for evaluating risk. A number of productivity and susceptibility attributes for a stock are used in a PSA and from these attributes, index scores and measures of uncertainty are computed and graphically displayed. To demonstrate the utility of the resulting vulnerability evaluation, we evaluated six U.S. fisheries targeting 162 stocks that exhibited varying degrees of productivity and susceptibility, and for which data quality varied. Overall, the PSA was capable of differentiating the vulnerability of stocks along the gradient of susceptibility and productivity indices, although fixed thresholds separating low-, moderate-, and highly vulnerable species were not observed. The PSA can be used as a flexible tool that can incorporate regional-specific information on fishery and management activity

Examining Mattering, Spiritual Mattering, and First-Year Retention at a Private, Religiously-Affiliated Institution of Higher Education

The primary purpose of this project was to explore how Schlossberg’s (1989) theory of college student’s mattering relates to college student retention in the context of a Christian institution of higher education. In addition, the authors created and tested a “spiritual mattering” measure based on Schlossberg’s theory. Mattering is a self-perception that refers to how important we believe we are to others. Schlossberg (1989) inserted this concept into the realm of higher education when she examined mattering and adult students returning to college. The purpose of the study was accomplished through the following three research objectives: a) Determining whether “institutional” mattering predicts fall-to-fall semester persistence of first-year students at a religiously-affiliated campus; b) Constructing a spiritual mattering measure and assessing its psychometric properties; and c) Determining whether spiritual mattering predicts fall-to-fall semester persistence of first-year students at a Christian institution of higher education. The results of the study supported the hypothesis that higher scores for both spiritual mattering and university mattering were significantly related to higher retention rates at an institution of higher education