21,602 research outputs found
Characterization of cereal products with fruit component for baby nutrition
Předložená bakalářská práce se zabývá charakterizací mléčných cereálních výrobků určených pro dětskou výživu. Teoretická část se zaměřuje na morfologii obilného zrna, dále na druhy fortifikace, na přehled přídavných složek používaných k fortifikaci a jejich vlastnosti. Pro praktickou část bylo vybráno 8 druhů mléčných cereálních výrobků od tří různých výrobců. U těchto výrobků byly spektrofotometrickými metodami analyzovány celkové polyfenoly, celkové flavonoidy, redukující i celkové sacharidy a proteiny. Nejvíce polyfenolů bylo naměřeno ve výrobku Sunar multicereální a nejvíce flavonoidů bylo zjištěno u výrobku Nestlé ovocné, kde představovaly přes 50 % celkového obsahu z polyfenolů. Nejvyšší obsah celkových i redukujících sacharidů obsahovala příchuť Nestlé medové. Nejvíce proteinů bylo naměřeno ve výrobcích značky Sunar, příchutě multicereální a hrušky se sušenkami. Metodou HPLC/UV-VIS byly stanoveny vitaminy C a E. Nejvíce vitaminu C obsahovala příchuť Nestlé sušenkové a nejvíce vitaminu E obsahovala příchuť Sunar hrušky se sušenkami. Metodou HPLC/RI byly analyzovány vybrané sacharidy. Ve všech výrobcích bylo vysoké zastoupení laktosy, nejvíce ve výrobcích Sunar. Výrobky Nestlé obsahovaly nejvíce glukosy. Výrobky od značky Hami byly nejvíce bohaté na sacharosu.Present bachelor thesis deals with the characterization of milk cereal products intended for baby food. The theoretical part focuses on the morphology of cereal grains, fortification, an overwiev of supplementary components used to fortification and their properties. For the practical part eight kinds of cereal dairy products of three different producers were chosen. In these products total polyphenols, total flavonoids, reducing and total saccharides and proteins were analyzed. The highest level of polyphenols was measured in product Sunar multicereal. The highest amount of flavonoids (more than 50 % of total phenolics) was found in Nestle fruit product. The highest level of total and reducing saccharides contained Nestlé honey flavour. High amount of proteins was found in products Sunar with multicereal flavour and pears with biscuits. Using HPLC/UV-VIS analysis vitamins C and E were determined. The highest content of vitamin C contained Nestlé with cookie lavor, while high vitamin E level was found in Sunar pear flavor and biscuits. Using HPLC/RI individual saccharides were examined. In all products high amount of lactose was found, mainly in the products of Sunar. Nestlé products contained mostly glukose, while in products Hami sucrose was detected as the most abundant saccharide.
A Survey on Homomorphic Encryption Schemes: Theory and Implementation
Legacy encryption systems depend on sharing a key (public or private) among
the peers involved in exchanging an encrypted message. However, this approach
poses privacy concerns. Especially with popular cloud services, the control
over the privacy of the sensitive data is lost. Even when the keys are not
shared, the encrypted material is shared with a third party that does not
necessarily need to access the content. Moreover, untrusted servers, providers,
and cloud operators can keep identifying elements of users long after users end
the relationship with the services. Indeed, Homomorphic Encryption (HE), a
special kind of encryption scheme, can address these concerns as it allows any
third party to operate on the encrypted data without decrypting it in advance.
Although this extremely useful feature of the HE scheme has been known for over
30 years, the first plausible and achievable Fully Homomorphic Encryption (FHE)
scheme, which allows any computable function to perform on the encrypted data,
was introduced by Craig Gentry in 2009. Even though this was a major
achievement, different implementations so far demonstrated that FHE still needs
to be improved significantly to be practical on every platform. First, we
present the basics of HE and the details of the well-known Partially
Homomorphic Encryption (PHE) and Somewhat Homomorphic Encryption (SWHE), which
are important pillars of achieving FHE. Then, the main FHE families, which have
become the base for the other follow-up FHE schemes are presented. Furthermore,
the implementations and recent improvements in Gentry-type FHE schemes are also
surveyed. Finally, further research directions are discussed. This survey is
intended to give a clear knowledge and foundation to researchers and
practitioners interested in knowing, applying, as well as extending the state
of the art HE, PHE, SWHE, and FHE systems.Comment: - Updated. (October 6, 2017) - This paper is an early draft of the
survey that is being submitted to ACM CSUR and has been uploaded to arXiv for
feedback from stakeholder
Sequential Circuit Design for Embedded Cryptographic Applications Resilient to Adversarial Faults
In the relatively young field of fault-tolerant cryptography, the main research effort has focused exclusively on the protection of the data path of cryptographic circuits. To date, however, we have not found any work that aims at protecting the control logic of these circuits against fault attacks, which thus remains the proverbial Achilles’ heel. Motivated by a hypothetical yet realistic fault analysis attack that, in principle, could be mounted against any modular exponentiation engine, even one with appropriate data path protection, we set out to close this remaining gap. In this paper, we present guidelines for the design of multifault-resilient sequential control logic based on standard Error-Detecting Codes (EDCs) with large minimum distance. We introduce a metric that measures the effectiveness of the error detection technique in terms of the effort the attacker has to make in relation to the area overhead spent in
implementing the EDC. Our comparison shows that the proposed EDC-based technique provides superior performance when compared against regular N-modular redundancy techniques. Furthermore, our technique scales well and does not affect the critical path delay
Transparent code authentication at the processor level
The authors present a lightweight authentication mechanism that verifies the authenticity of code and thereby addresses the virus and malicious code problems at the hardware level eliminating the need for trusted extensions in the operating system. The technique proposed tightly integrates the authentication mechanism into the processor core. The authentication latency is hidden behind the memory access latency, thereby allowing seamless on-the-fly authentication of instructions. In addition, the proposed authentication method supports seamless encryption of code (and static data). Consequently, while providing the software users with assurance for authenticity of programs executing on their hardware, the proposed technique also protects the software manufacturers’ intellectual property through encryption. The performance analysis shows that, under mild assumptions, the presented technique introduces negligible overhead for even moderate cache sizes
Revealing the unseen: how to expose cloud usage while protecting user privacy
Cloud users have little visibility into the performance characteristics and utilization of the physical machines underpinning the virtualized cloud resources they use. This uncertainty forces users and researchers to reverse engineer the inner workings of cloud systems in order to understand and optimize the conditions their applications operate. At Massachusetts Open Cloud (MOC), as a public cloud operator, we'd like to expose the utilization of our physical infrastructure to stop this wasteful effort. Mindful that such exposure can be used maliciously for gaining insight into other user's workloads, in this position paper we argue for the need for an approach that balances openness of the cloud overall with privacy for each tenant inside of it. We believe that this approach can be instantiated via a novel combination of several security and privacy technologies. We discuss the potential benefits, implications of transparency for cloud systems and users, and technical challenges/possibilities.Accepted manuscrip
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