This study focused on how local politicians in Kalmar perceive journalists and their intertwined relationship. We based our study on the theoretical understanding of today’s media-centric democratic society. The ‘adversary model’ offered an understanding of the intricate relations between politicians and journalists. The relationship builds on constant trade where both parties are dependent on each other. Politicians exchange information to gain attention in the media. Journalists needs politicians as important sources of information and have the power to control the exposure that politicians get in the public eye. This study was researched and conducted through qualitative interviews with local politicians. We found that experienced politicians have developed an understanding for journalistic work and that it is important to have a good relationship to reach out to their constituency. This professional relationship has to be kept at arm’s length as it otherwise risks to become too muddled. We learned that politicians are well aware of the need to adapt to media conditions – there were, however, examples of breakdowns in this precarious relationship. The politicians in our study delivered several examples of how media adaptation is managed, e g how press conferences are scheduled according to media deadlines and are held at suitable locations so that photographers can get good pictures. Trust appeared to be the crucial condition for a rewarding relationship. Every politician in our study agreed that it is all a question of trust.

Univ., Diss.--Paris.

<p>This study focused on how local politicians in Kalmar perceive journalists and their intertwined relationship. We based our study on the theoretical understanding of today’s media-centric democratic society. The ‘adversary model’ offered an understanding of the intricate relations between politicians and journalists. The relationship builds on constant trade where both parties are dependent on each other. Politicians exchange information to gain attention in the media. Journalists needs politicians as important sources of information and have the power to control the exposure that politicians get in the public eye. This study was researched and conducted through qualitative interviews with local politicians.</p><p>We found that experienced politicians have developed an understanding for journalistic work and that it is important to have a good relationship to reach out to their constituency. This professional relationship has to be kept at arm’s length as it otherwise risks to become too muddled. We learned that politicians are well aware of the need to adapt to media conditions – there were, however, examples of breakdowns in this precarious relationship.</p><p>The politicians in our study delivered several examples of how media adaptation is managed, e g how press conferences are scheduled according to media deadlines and are held at suitable locations so that photographers can get good pictures. Trust appeared to be the crucial condition for a rewarding relationship. Every politician in our study agreed that it is all a question of trust.</p>

In the field of cybersecurity, it is often not possible to construct systems that are resistant to all attacks. For example, even a well-designed password authentication system will be vulnerable to password cracking attacks because users tend to select low-entropy passwords. In the field of cryptography, we often model attackers as powerful and malicious and say that a system is broken if any such attacker can violate the desired security properties. While this approach is useful in some settings, such a high bar is unachievable in many security applications e.g., password authentication. However, even when the system is imperfectly secure, it may be possible to deter a rational attacker who seeks to maximize their utility. In particular, if a rational adversary finds that the cost of running an attack is higher than their expected rewards, they will not run that particular attack. In this dissertation we argue in support of the following statement: Modeling adversaries as rational actors can be used to better model the security of imperfect systems and develop stronger defenses. We present several results in support of this thesis. First, we develop models for the behavior of rational adversaries in the context of password cracking and quantum key-recovery attacks. These models allow us to quantify the damage caused by password breaches, quantify the damage caused by (widespread) password length leakage, and identify imperfectly secure settings where a rational adversary is unlikely to run any attacks i.e. quantum key-recovery attacks. Second, we develop several tools to deter rational attackers by ensuring the utility-optimizing attack is either less severe or nonexistent. Specifically, we develop tools that increase the cost of offline password cracking attacks by strengthening password hashing algorithms, strategically signaling user password strength, and using dedicated Application-Specific Integrated Circuits (ASICs) to store passwords.

No description available.

The study is a descriptive analysis using a case-study methodology that identifies the critical elements (methods, tools, processes, personnel, and practices) of adversary analysis identified as a red team and red-teaming. A red team is the adversary element of the analytic method of red-teaming. The study incorporates interview data with organization leadership, subject matter experts, and red-team developers from Department of Defense (DoD), Intelligence Community (IC), and Federally Funded Research and Development Centers (FFRDC) organizations. The study also includes red-team governance documents, red-team briefings, and discussions to first identify the concepts, analyze the critical design elements of the concept(s), and develop a fundamental taxonomy or classification of red-team approaches based on these artifacts. The study compares and contrasts four red teams that utilize groups of adversary subject-matter experts for common themes, differences, and best practices. The data collection builds on grounded theory—i.e., identification of the methods, tools, processes, and personnel as the organizations understand and develop their red teams as part of their red-teaming analyses to address gaps in understanding possible adversaries. The four organizations studied are the U.S. Army, Training and Doctrine Command, University of Foreign Military and Cultural Studies; a Department of Defense unified combatant command; the U.S. Naval War College (NWC) and its red-team detachment; and a Sandia National Laboratories (SNL) Homeland Security and Defense, National Infrastructure Simulation and Analysis Center (NISAC). Two basic types of red teams are identified from the data with a hybrid between the two among the variations of the red-teaming concept. Some of the other findings from the four red teams include a need to develop common terms and standards; a need to explain the benefits of alternative analysis to decisionmakers; a need to develop trend analyses on types of red teams requested by sponsors; a need to design methods to capture non-state actors; a need to include more coalition and foreign partners; and a need to immerse red teams more fully into the culture to be understood. / Ph. D.

<p dir="ltr">We analyze the query complexity of multiple search problems.</p><p dir="ltr">Firstly, we provide lower bounds on the complexity of "Local Search". In local search we are given a graph G and oracle access to a function f mapping the vertices to numbers, and seek a local minimum of f; i.e. a vertex v such that f(v) <= f(u) for all neighbors u of v. We provide separate lower bounds in terms of several graph parameters, including congestion, expansion, separation number, mixing time of a random walk, and spectral gap. To aid in showing these bounds, we design and use an improved relational adversary method for classical algorithms, building on the prior work of Scott Aaronson. We also obtain some quantum bounds using the traditional strong weighted adversary method.</p><p dir="ltr">Secondly, we show a multiplicative duality gap for Yao's minimax lemma by studying unordered search. We then go on to give tighter than asymptotic bounds for unordered and ordered search in rounds. Inspired by a connection through sorting with rank queries, we also provide tight asymptotic bounds for proportional cake cutting in rounds.</p>

Nous abordons des problèmes de sécurité dans des systèmes cyber-physiques industriels. Les attaques contre ces systèmes doivent être traitées à la fois en matière de sûreté et de sécurité. Les technologies de contrôles imposés par les normes industrielles, couvrent déjà la sûreté. Cependant, du point de vue de la sécurité, la littérature a prouvé que l’utilisation de techniques cyber pour traiter la sécurité de ces systèmes n’est pas suffisante, car les actions physiques malveillantes seront ignorées. Pour cette raison, on a besoin de mécanismes pour protéger les deux couches à la fois. Certains auteurs ont traité des attaques de rejeu et d’intégrité en utilisant une attestation physique, p. ex., le tatouage des paramètres physiques du système. Néanmoins, ces détecteurs fonctionnent correctement uniquement si les adversaires n’ont pas assez de connaissances pour tromper les deux couches. Cette thèse porte sur les limites mentionnées ci-dessus. Nous commençons en testant l’efficacité d’un détecteur qui utilise une signature stationnaire afin de détecter des actions malveillantes. Nous montrons que ce détecteur est incapable d’identifier les adversaires cyber-physiques qui tentent de connaître la dynamique du système. Nous analysons son ratio de détection sous la présence de nouveaux adversaires capables de déduire la dynamique du système. Nous revisitons le design original, en utilisant une signature non stationnaire, afin de gérer les adversaires visant à échapper à la détection. Nous proposons également une nouvelle approche qui combine des stratégies de contrôle et de communication. Toutes les solutions son validées à l’aide de simulations et maquettes d’entraînement / We address security issues in cyber-physical industrial systems. Attacks against these systems shall be handled both in terms of safety and security. Control technologies imposed by industrial standards already cover the safety dimension. From a security standpoint, the literature has shown that using only cyber information to handle the security of cyber-physical systems is not enough, since physical malicious actions are ignored. For this reason, cyber-physical systems have to be protected from threats to their cyber and physical layers. Some authors handle the attacks by using physical attestations of the underlying processes, f.i., physical watermarking to ensure the truthfulness of the process. However, these detectors work properly only if the adversaries do not have enough knowledge to mislead crosslayer data. This thesis focuses on the aforementioned limitations. It starts by testing the effectiveness of a stationary watermark-based fault detector, to detect, as well, malicious actions produced by adversaries. We show that the stationary watermark-based detector is unable to identify cyber-physical adversaries. We show that the approach only detects adversaries that do not attempt to get any knowledge about the system dynamics. We analyze the detection performance of the original design under the presence of adversaries that infer the system dynamics to evade detection. We revisit the original design, using a non-stationary watermark-based design, to handle those adversaries. We also propose a novel approach that combines control and communication strategies. We validate our solutions using numeric simulations and training cyber-physical testbeds

In the context of error control in random linear network coding, it is useful to construct codes that comprise well-separated collections of subspaces of a vector space over a finite field. This thesis concerns the construction of non-constant-dimension projective space codes for adversarial error-correction in random linear network coding. The metric used is the so-called injection distance introduced by Silva and Kschischang, which perfectly reflects the adversarial nature of the channel. A Gilbert-Varshamov-type bound for such codes is derived and its asymptotic behaviour is analysed. It is shown that in the limit as the ambient space dimension approaches infinity, the Gilbert-Varshamov bound on the size of non-constant-dimension codes behaves similar to the Gilbert-Varshamov bound on the size of constant-dimension codes contained within the largest Grassmannians in the projective space. Using the code-construction framework of Etzion and Silberstein, new non-constant-dimension codes are constructed; these codes contain more codewords than comparable codes designed for the subspace metric. To our knowledge this work is the first to address the construction of non-constant-dimension codes designed for the injection metric.

In the context of error control in random linear network coding, it is useful to construct codes that comprise well-separated collections of subspaces of a vector space over a finite field. This thesis concerns the construction of non-constant-dimension projective space codes for adversarial error-correction in random linear network coding. The metric used is the so-called injection distance introduced by Silva and Kschischang, which perfectly reflects the adversarial nature of the channel. A Gilbert-Varshamov-type bound for such codes is derived and its asymptotic behaviour is analysed. It is shown that in the limit as the ambient space dimension approaches infinity, the Gilbert-Varshamov bound on the size of non-constant-dimension codes behaves similar to the Gilbert-Varshamov bound on the size of constant-dimension codes contained within the largest Grassmannians in the projective space. Using the code-construction framework of Etzion and Silberstein, new non-constant-dimension codes are constructed; these codes contain more codewords than comparable codes designed for the subspace metric. To our knowledge this work is the first to address the construction of non-constant-dimension codes designed for the injection metric.