Semantics-Based Cache-Side-Channel Quantification in Cryptographic Implementations

Performance has been and will continue to be a key criterion in the development of computer systems for a long time. To speed up Central Processing Units (CPUs), micro-architectural components like, e.g., caches and instruction pipelines have been developed. While caches are indispensable from a performance perspective, they also introduce a security risk. If the interaction of a software implementation with a cache differs depending on the data processed by the software, an attacker who observes this interaction can deduce information about the processed data. If the dependence is unintentional, it is called a cache side channel. Cache side channels have been exploited to recover entire secret keys from numerous cryptographic implementations. There are ways to mitigate the leakage of secret information like, e.g., crypto keys through cache side channels. However, such mitigations come at the cost of performance loss, because they cancel out the performance benefits of caching either selectively or completely. That is, there is a security-performance trade-off that is inherent in the mitigation of cache-side-channel leakage. This security-performance trade-off can only be navigated in an informed fashion if reliable quantitative information on the cache-side-channel security of an implementation is available. Quantitative security guarantees can be computed based on program analyses. However, the existing analyses either do not consider caches, do not provide quantitative guarantees across all side-channel output values, or are only applicable to a limited range of crypto implementations. In this thesis, we propose a suite of program analyses that can provide quantitative security guarantees in the form of reliable upper bounds on the cache-side-channel leakage of a variety of real-world cryptographic implementations. Technically, our program analyses are based on a combination of information theory and abstract interpretation. The distinguishing feature of each analysis is the underlying abstraction of the execution environment and program semantics. Our first program analysis is based on an abstraction that captures the state of a CPU with a regular Arithmetic Logic Unit (ALU) during the execution of x86 instructions. In particular, our abstraction captures two status flags that are used, e.g., during the execution of different AES implementations. Our analysis is capable of computing quantitative cache-side-channel security guarantees for off-the-shelf AES implementations from multiple popular libraries. In a comparative study, we clarify the security impact of design choices in these implementations. For instance, we find that the number and size of lookup tables used for just the last transformation round of AES already has a significant impact on the guarantees for the entire implementation. Our second program analysis is based on an abstraction that captures the execution of additional x86 instructions, including instructions that process larger operands. This abstraction can be used to quantify the leakage of crypto implementations that are based on large parameters. For instance, the lattice-based signature scheme ring-TESLA has a maximum key size of 49152 bit. With our analysis, we successfully computed leakage bounds for the implementation of ring-TESLA. These bounds lead to the detection of multiple vulnerabilities that might be exploited to break the entire signature scheme. As a result, mitigations were integrated into the implementations of ring-TESLA and qTESLA, before the latter was submitted to the NIST PQC standardization. Our third program analysis is based on an abstraction that captures the state of a CPU with an ALU and a Floating-Point Unit. It can be used to compute leakage bounds for crypto implementations that rely on floating-point instructions, e.g., to compute probabilities. The software used in Quantum Key Distribution (QKD), e.g., heavily relies on probabilities to perform error correction. With our analysis, we computed leakage bounds for a QKD implementation and detected a vulnerability that might leak the entire secret key. We proposed a mitigation and verified its effectiveness using our analysis. In the new version of the implementation, which is used at the TU Darmstadt Department of Physics, our mitigation is already integrated. Finally, we broaden the scope to side channels that arise from the combination of caching and instruction pipelining. Such side channels are exploited, e.g., by the Spectre-PHT attack. The fourth program analysis in our suite is, to our knowledge, the first ever program analysis that computes reliable quantitative security guarantees with respect to such side channels

The Conventions and Regulation of Book Culture

THE PRODUCTION, RECEPTION AND CONSUMPTION OF BOOKS ARE SHAPED BY COMPLEX systems of policy, conventions and traditions. These range from formally consecrated legislation and official industry and organisational codes of conduct, through to those conventions that govern literary merit, genres, questions of ‘taste’, and the value placed on the book as a cultural object. This special section of the Australian Humanities Review explores the ways—both tacit and explicit—in which book culture is regulated, with a particular focus on contemporary Australian book publishing. The essays engage with the laws of book culture, identifying these formal and informal rules, and exploring how they influence the workings of the field

Exploring the Relationships between Hemoglobin, the Endothelium and Vascular Health in Patients with Chronic Kidney Disease

Background/Aims: The ideal hemoglobin target in chronic kidney disease remains unknown. Ultimately, individualized targets may depend upon the properties of the patient’s endothelial and vascular milieu, and thus the complex relationships between these factors need to be further explored. Methods: Forty-six patients with a glomerular filtration rate (GFR) 2 or on renal replacement therapy underwent measurement of hemoglobin, endothelial microparticles (EMPs) and aortic pulse wave velocity (PWV) at 0, 3 and 6 months. In addition, a number of inflammatory, cardiac and vascular biomarkers were measured at baseline. Results: No correlation was observed between baseline values of PWV and EMPs, PWV and hemoglobin, or hemoglobin and EMPs in the overall cohort. When stratified by CKD status, a positive correlation was observed between PWV and EMP CD41–/CD144+ in patients with GFR 2 only (r = 0.54, p = 0.01). Asymmetric dimethylarginine correlated with baseline PWV (r = 0.27, p = 0.07), and remained significantly correlated with the 3- and 6-month PWV measurement. Conclusions: In this small heterogeneous cohort of dialysis and non-dialysis patients, we were unable to describe a physiologic link between anemia, endothelial dysfunction and arterial stiffness

In-situ phase diagram determination of the HfO2-Ta2O5 binary up to 3000˚C

Ceramic equilibrium phase diagrams have proven to be difficult to produce for materials above 1500 ˚C. We demonstrate that in-situ X-ray diffraction on laser heated levitated samples can be used to elucidate phase fields. In these experiments, solid spherical samples are suspended and rotated by a gas stream through a conical nozzle levitator, heated by a 400 W CO2 laser at Argonne National Labs beamline 6-ID-D. Please click on the link below for the full content

A moda e as modistas em Portugal durante o Estado Novo : as mudanças do pós-guerra (1945-1974)

Propomo-nos, na presente dissertação, contextualizar e apresentar a Moda em Portugal, durante um período assinalável do regime político que em Portugal se designou Estado Novo (1945-1974), com destaque para as influências que recebeu e para as modistas portuguesas que constituíram um marco importante para a Moda nacional nesse tempo. Para tal, serão indicados objectivos específicos de forma a enquadrar o tema de estudo deste trabalho. Começaremos por traçar um enquadramento relativo ao período histórico a ser estudado, fazendo assim a ponte entre a mulher portuguesa, no Estado Novo, o seu estatuto social e o seu contexto na Segunda Guerra Mundial ao fim da ditadura. De seguida, abordaremos o ponto principal da nossa dissertação: a Moda e as Modistas em Portugal no Estado Novo. Este aspecto é fundamental para fazer a ligação entre a moda em Portugal e no estrangeiro, com especial incidência na moda em Paris, uma vez que constituía a maior referência para as mulheres portuguesas da época. Em Portugal, desenvolveram-se várias “Casas de Costura” orientadas por pessoas ditas de “muito bom gosto”, numa altura em que a formação especializada na criação de moda era inexistente no nosso país. De entre as várias Casas de Costura, destacaram-se, em Lisboa, a da Bobone, a da Ana Maravilhas e a da Beatriz Chagas. No Porto, a casa de maior referência é a da Candidinha, cujo nome era incontornável na moda da época. Existiram outras, mas a esta última foi a única que estendeu o seu negócio até à capital. Ainda dentro deste capítulo, faremos referência aos clientes e ao mercado neste sector na época em estudo, onde daremos destaque ao Chiado como centro da Moda em Lisboa e zona privilegiada de aquisição da matéria-prima utilizada na concepção de vestuário. Era também no Chiado que se localizavam os grandes armazéns que divulgavam os últimos figurinos vindos de Paris. Ao falarmos do Chiado e das grandes casas e armazéns que forneciam os tecidos e onde as modistas os adquiriam, não poderemos deixar de referir os desfiles de moda aos quais, na altura, era dada uma grande importância. Para além de haver desfiles nos Grandes Armazéns do Chiado e Grandella, também aconteceram outros, com elevada importância, em edifícios históricos e/ou com elevado interesse arquitectónico e artístico como o Palácio Foz, o Coliseu dos Recreios, o Hotel Ritz, o Casino Estoril e o Palace Hotel (Hotel Palácio do Estoril). Neste último caso, os desfiles ocorreram mais na década de 1960, quando a moda atingiu o seu auge. No período em estudo, a moda feminina, além de muito difundida através das revistas da especialidade (magazines) fonte à qual dedicamos a nossa análise, foi também representada na Pintura de Retrato. Constatado este facto, considerámos pertinente fazer uma abordagem particular a esta fonte iconográfica. Dois pintores de grande referência e aos quais vamos dar destaque como exemplo foram Eduardo Malta (1900-1968) e Henrique Medina (1901-1988), devido ao seu extenso trabalho enquanto retratistas. Em relação ao primeiro, acresce a relação de proximidade que desenvolveu com Oliveira Salazar, a quem retratou. Concluiremos a dissertação fazendo uma menção ao Museu Nacional do Traje, considerado uma instituição pública de referência no que concerne ao traje e à moda em Portugal. Ainda que inaugurado em 1977, o projecto ideológico subjacente à sua criação remete para a década anterior. Assim, ao mesmo tempo que os anos 60 correspondem, a um período de liberdade no domínio da indumentária, traduzindo-se na abertura de casas de Alta-costura no nosso país, cuja revolução continua na década seguinte, originando o romper com os antigos conceitos da elegância e do chique, também se proclama a valorização, conhecimento e divulgação da moda do passado. Em Portugal seguiu-se assim, ainda que tardiamente, o exemplo de outros países onde existiam museus especializados na temática do traje, nomeadamente em Paris com o Musée de la Mode et du Textile, fundado em 1905 e em Madrid com Museo del Traje e Regional e Histórico, fundado em 1925.We propose in the dissertation, contextualize and present the Fashion in Portugal for a considerable period of the political regime in Portugal that was designated Estado Novo (1945-1974), the influences he received and the Portuguese dressmakers that were an important milestone for the national Fashion in that time. Such, will be given specific objectives in order to frame the study subject of this work. We start by getting an overview on the historical period to be studied, thus bridging the gap between the Portuguese woman in the Estado Novo, its social status and its context in the Second World War to the end of the dictatorship. After making a historical context, we started by the main point of our dissertation: the Fashion and Dressmaker’s in Portugal in the Estado Novo period. In addressing this aspect, it is important and essential to make the connection between fashion in Portugal and abroad, with particular emphasis on fashion in Paris, since it was the major reference for fashion and for Portuguese women. In Portugal, several Dressmaker’s were developed and guided by people of "good taste", once specialized training in fashion creation was non-existent in our country. Among the various Dressmaker’s, the one’s that stood out in Lisbon, were Bobone, Anna Maravilhas and Beatriz Chagas. In Oporto, the reference is Candidinha whose name was unavoidable in the fashion at the time, however, there were also others, but Candidinha Couture House was the only one that extended its business to the capital. Also within this chapter we will make reference to the customers and the market in this sector in the study period, where we will highlight Chiado as Lisbon fashion centre and a privileged area for acquisition of material used in High Fashion. The Chiado where were located the great department stores who promote the last costumes coming from Paris. When we speak about Chiado, the great houses and the department stores that supplied the fabrics and where the Dressmakers acquired them, we cannot fail to mention the fashion shows to which, at the time, was given great importance. Besides having fashion shows in Chiado and Grandella department stores also they occurred with great importance at historical buildings such as the Palácio Foz, Coliseu dos Recreios, Hotel Ritz, Casino Estoril and the Palace Hotel (Hotel Palácio in Estoril), here more in the decade of 60, when fashion was at its peak. At the time, women´s fashion, in addition to being very popular through the specialized magazines source to which we dedicated our analysis, was also represented in Portrait Painting. Given this fact, we considered it relevant to take a particular approach to this iconographic source. Two prominent painters to whom we will highlight as examples were Eduardo Malta (1900-1968) and Henrique Medina (1901-1988), due to there extensive work as portraitists. In relation to the first, it adds the close relationship developed with Oliveira Salazar, whom he portrayed. We conclude the dissertation by mentioning the Museu Nacional do Traje (National Costume Museum), considered a public institution of reference regarding dress and fashion in Portugal. Although inaugurated in 1977, the ideological project that underlies its creation dates back to the previous decade. Thus, at the same time as the 60's correspond to a period of freedom in the field of clothing, translating into the opening of Haute Couture houses in our country, whose revolution continues in the following decade, leading to break with the old concepts Elegance and chic, it is also proclaimed the appreciation, knowledge and popularization of the fashion of the past. In Portugal, there followed, albeit belatedly, the example of other countries where there were museums specialized in the theme of costume, namely in Paris with the Musée de la Mode et du Textile, founded in 1905 and in Madrid with the Costume and Regional Museum And History, founded in 1925

The Structure of Liquid and Amorphous Hafnia.

Understanding the atomic structure of amorphous solids is important in predicting and tuning their macroscopic behavior. Here, we use a combination of high-energy X-ray diffraction, neutron diffraction, and molecular dynamics simulations to benchmark the atomic interactions in the high temperature stable liquid and low-density amorphous solid states of hafnia. The diffraction results reveal an average Hf-O coordination number of ~7 exists in both the liquid and amorphous nanoparticle forms studied. The measured pair distribution functions are compared to those generated from several simulation models in the literature. We have also performed ab initio and classical molecular dynamics simulations that show density has a strong effect on the polyhedral connectivity. The liquid shows a broad distribution of Hf-Hf interactions, while the formation of low-density amorphous nanoclusters can reproduce the sharp split peak in the Hf-Hf partial pair distribution function observed in experiment. The agglomeration of amorphous nanoparticles condensed from the gas phase is associated with the formation of both edge-sharing and corner-sharing HfO6,7 polyhedra resembling that observed in the monoclinic phase