Secure Messaging with in-app user defined schemes

Cryptography has been the culmination of human trials and mistrials in an attempt to keep information safe from unintended access. We have learned from our mistakes in the past, and today with the help of both academician and software developers, we have robust cryptographic technologies. Cryptography however, is a race between increasing processing power of modern machines and the complexity of cryptographic systems. With quantum computing on the horizon, our present cryptographic systems seem to fall behind in this race. There is a need to catalyze research in the field. Here, an application is proposed, which empowers users to write their own cryptographic schemes. It hopes to create a platform where people can share their cryptographic schemes and have an application that can help them share information securely. The author hopes, that an application which sources cryptographic schemes from users, would help catalyze research in the field. An application where the security implementation is dependent on the whim of the user could prove a hard target for attack. The thesis starts with a preliminary study of the Android platform. The thesis then analyzes im- plementations of a few secure messaging applications and then delves into details of NFC. Using the background information accumulated during the course of this study, the authors attempt to formulate a sound implementation of a messaging application. The thesis is also accompanied with a proof-of-concept Android application that checks the viability of concepts discussed herein

ELECTRICAL AND MECHANICAL PROPERTIES OF MWCNT FILLED CONDUCTIVE ADHESIVES ON LEAD FREE SURFACE FINISHED PCB\u27s.

Electrically conductive adhesives (ECA) are an alternative to tin/lead solders for attaching Surface Mount Devices (SMD) in electronic assemblies. ECAs are mixtures of a polymer binder (for adhesion) and conductive filler (for electrical conductivity). They bring more conductivity, higher strength, less weight and longer durability than metal alloys. ECAs can offer numerous advantages such as fewer processing steps, lower processing temperature and fine pitch capability. Multi walled carbon nanotubes (MWCNT) were used as conductive fillers in this research because of their novel electronic and mechanical properties. The high aspect ratio of the nanotubes makes it possible to percolate at low loadings to obtain good electrical and mechanical properties. Replacing the metal filler with CNTs in the adhesive made the ECA light weight, corrosion resistant, reduced processing temperature, lead free, electrically conductive and high mechanical strength. The MWCNTs at different loadings were mixed with epoxy and epoxy: heloxy to form a composite mixture. Different loadings, additives and mixing methods were used to obtain good electrical and mechanical properties and pot life. Pressure dispensing, screen and stencil printing were the processing techniques used for making the samples. The volume resistivity, contact resistance, die shear and lap shear tests were conducted on different surface finished Printed Circuit Boards (PCB) like silver, tin and Electro less Nickel Immersion Gold (ENIG). The results are summarized and compared with traditional methods

Competing in Markets with Digital Convergence: Product Differentiation, Platform Scope and Equilibrium Structure

The incorporation of digital technologies into the products of diverse industries, accompanied by a shift to von-Neumann-like platform architectures, while resulting in substantially more valuable and flexible products, also leads to increased substitutability across previously distinct markets. This paper analyzes the economic implications of this trade-off in technology markets subject to digital convergence. We present a new model of imperfect competition that captures flexible platform scope, variability in consumer requirements, and multiple product purchases. We specify four types of equilibrium configurations - local monopoly, kinked, competitive and non-exclusive - that emerge as outcomes of the model, and describe how each equilibrium structure characterizes a distinct stage of digital convergence. Our analysis establishes that as markets converge, prices always rise initially even as competing products become less differentiated. However, when platform scope is largely dictated by exogenous factors, prices and profits eventually fall as the stage of convergence progresses, though consumer surplus and total surplus rise. Furthermore, while convergence has the expected effect of shifting consumption patterns from purchasing multiple specialized products to buying a single general-purpose product, we describe examples of equilibria in which consumers may buy multiple general-purpose products, using each for a specialized subset of their requirements. Pricing responses to changes in variable costs and consumer functionality needs are also discussed. When firms can make strategic choices of platform scope, we show that in any subgame perfect equilibrium, duopoly prices are always higher than monopoly prices, and industries may sustain high levels of profitability even when their boundaries blur. We also establish that as technological progress lowers fixed costs, a natural outcome is for unregulated firms to over-invest in platform scope relative to the social optimum, and that this outcome is true under both monopoly and duopoly market structuresInformation Systems Working Papers Serie

Product Scope and Entry Deterrence in Technology Markets

We model an oligopolistic technology market in which firms endogenously choose product scope, fixed costs are affected by exogenous technological progress, and there may be threat of entry. Our analysis shows that equilibrium outcomes involve substantial overinvestment in product scope, which benefit consumers and hurt firms, relative to the social optimum. Technological progress generally increases consumer surplus and lowers firm profits. If entry is threatened bilaterally across two converging markets, both either accommodate entrants from the rival market, or both deter entry; continuous progress in technology can cause equilibria shifts, leading to discontinuous and radical redistribution of surplus across markets.Information Systems Working Papers Serie

Market Expansion or Margin Erosion: The Double-Edged Sword of Digital Convergence

Digital convergence enables firms in the computing, communications, and electronic consumer industries to design and launch multifunctional converged products. This presents firms with a significant opportunity for value creation and profit growth. At the same time, the increased substitutability between products supplied by different industry segments heightens competition and poses a significant threat of margin erosion. These conflicting incentives make it difficult for firms in converging industries to make strategic product line and product design decisions. In our study, we analyze the technological, product, and market factors that have an impact on these decisions and derive conditions under which it is (and is not) optimal for firms to launch converged products that combine the functionalities of products in two different industries. We find that the optimality of including converged products in the product line depends crucially on the synergies arising out of functionality colocation. Further, as technology permits higher levels of product convergence, converged products relegate specialized products to narrow market niches, even when there is some quality degradation from functionality colocation. Overall production and total firm profits tend to increase, although the impact on consumer surplus and total welfare is ambiguous

Leadership Training In An MBA Program Using Peer-led Team Learning

Leadership training is an important part of any MBA program, but is often difficult to provide in an effective way. Over the last three years, we implemented a program of Peer-Led Team Learning in two core courses of our MBA curriculum, which we believe provides a good solution. The program combines leadership training with practical hands-on application of the ideas taught, and provides for an effective feedback loop. Response to the program has been overwhelmingly positive. The program and benefits for learning leadership are discussed in this paper

ANTI INFLAMMATORY ACTIVITY OF ERYTHRINA VARIEGATA

Objective: Erythrina variegata had been widely used for its reported biological activity in indigenous system of medicine. The present investigation was carried out to find the anti-inflammatory effect of ethanolic extract of Erythrina variegata in albino rats.Methods: The anti-inflammatory activity was evaluated using acute inflammatory model like carrageenan induced paw edema and chronic inflammatory model like cotton pellet induced granuloma respectively.Results: The ethanolic extract in different doses (200, and 400mg/kg, p. o) exhibited dose dependent and significant antiinflammatory activity in acute and chronic model of inflammation.Conclusion: The alcoholic extract of Erythrina variegata has anti-inflammatory activity. This activity was related to the dose and these results corroborate the potential traditional use of the plant in folk medicine

Silymarin Protects Epidermal Keratinocytes from Ultraviolet Radiation-Induced Apoptosis and DNA Damage by Nucleotide Excision Repair Mechanism

Solar ultraviolet (UV) radiation is a well recognized epidemiologic risk factor for melanoma and non-melanoma skin cancers. This observation has been linked to the accumulation of UVB radiation-induced DNA lesions in cells, and that finally lead to the development of skin cancers. Earlier, we have shown that topical treatment of skin with silymarin, a plant flavanoid from milk thistle (Silybum marianum), inhibits photocarcinogenesis in mice; however it is less understood whether chemopreventive effect of silymarin is mediated through the repair of DNA lesions in skin cells and that protect the cells from apoptosis. Here, we show that treatment of normal human epidermal keratinocytes (NHEK) with silymarin blocks UVB-induced apoptosis of NHEK in vitro. Silymarin reduces the amount of UVB radiation-induced DNA damage as demonstrated by reduced amounts of cyclobutane pyrimidine dimers (CPDs) and as measured by comet assay, and that ultimately may lead to reduced apoptosis of NHEK. The reduction of UV radiation-induced DNA damage by silymarin appears to be related with induction of nucleotide excision repair (NER) genes, because UV radiation-induced apoptosis was not blocked by silymarin in NER-deficient human fibroblasts. Cytostaining and dot-blot analysis revealed that silymarin repaired UV-induced CPDs in NER-proficient fibroblasts from a healthy individual but did not repair UV-induced CPD-positive cells in NER-deficient fibroblasts from patients suffering from xeroderma pigmentosum complementation-A disease. Similarly, immunohistochemical analysis revealed that silymarin did not reduce the number of UVB-induced sunburn/apoptotic cells in the skin of NER-deficient mice, but reduced the number of sunburn cells in their wild-type counterparts. Together, these results suggest that silymarin exert the capacity to reduce UV radiation-induced DNA damage and, thus, prevent the harmful effects of UV radiation on the genomic stability of epidermal cells