La généralisation de l’usage d’Internet et le développement simultané du web 2.0 avec l’apparition des réseaux sociaux numériques (RSN) ont conduit à l’apparition d’une présence numérique pour les internautes : l’identité numérique (IN). Constituée d’une superposition d’identités faites de données personnelles, déclaratives et comportementales, cette nouvelle forme d’identité est caractérisée par des modes d’expression de soi divers particulièrement visibles sur les RSN et en particulier sur le site Facebook. Simultanément, l’affranchissement de l’individu des cadres sociaux traditionnels le conduit à faire et défaire son identité qu’il envisage désormais comme un processus de construction identitaire (CI) fondé sur une recherche de repères et de relations. Ces nouveaux enjeux liés à l’identité conduisent à une évolution des liens entre CI et consommation. Celle-ci apparait en effet majeure pour la CI par les récits de soi qu’elle permet aux consommateurs. Ces mutations contraignent les entreprises à repenser leurs stratégies de marque établies depuis les années 50. Ces stratégies, centrées sur la quête d’attention du consommateur, s’attachent à individualiser le dialogue et à créer des contenus générant de l’interaction avec les publics ciblés. Dans cette optique, par ses caractéristiques et ses manifestations, l’IN est susceptible d’éclairer la prise en compte de nouveaux modes de présence des marques. À travers trois propositions théoriques, l’IN est envisagée au centre des perspectives d’innovation des marques ; l’analyse qualitative et quantitative de données collectées auprès des jeunes adultes a donné lieu à des apports théoriques liés aux modes de CI contemporaine et à des apports managériaux relatifs à l’élaboration de nouvelles stratégies de communication sur Internet. / The spread of the Internet and the simultaneous development of Web 2.0 together with the advent of digital social networks (DSN) have led to the emergence of a digital presence for internet users: digital identity (DI). Consisting of a superposition of identities born from personal, declarative and behavioral data, this new form of identity is characterized by various highly patterns of self-expression on the DSN and in particular on Facebook. Simultaneously, the emancipation of the individual from traditional social frameworks leads that individual to construct and re-shape his or her identity which is now seen as a process of identity construction (IC) based on a search for benchmarks and relationships. These new identity issues lead to a modification in the relationship between IC and consumption. Indeed, this modification appears to have a major effect on IC through the self-image (or images) consumers are able to project. These changes are forcing companies to rethink the branding strategies they laid down back in the 50s. These strategies, focusing on the quest for consumer’s attention, endeavor to set up personalized rapports and create content that generates interaction with their targets. To this end, through its characteristics and in all its forms, DI could very well open the path to new ways of brand presence being taken into account. In the light of three theoretical proposals, DI is considered as being central to brand innovation perspectives; qualitative and quantitative analysis of data collected from young adults resulted in three theoretical contributions related to the IC modes of the contemporary individual and to three managerial input on the development of new strategies for communication on the Internet.

Tato dizertační práce se zabývá kryptografickými prostředky pro autentizaci. Hlavním tématem však nejsou klasické autentizační protokoly, které nabízejí pouze ověření identity, ale tzv. atributové autentizační systémy, pomocí kterých mohou uživatelé prokazovat svoje osobní atributy. Tyto atributy pak mohou představovat jakékoliv osobní informace, např. věk, národnost či místo narození. Atributy mohou být prokazovány anonymně a s podporou mnoha funkcí na ochranu digitální identity. Mezi takové funkce patří např. nespojitelnost autentizačních relací, nesledovatelnost, možnost výběru prokazovaných atributů či efektivní revokace. Atributové autentizační systémy jsou již nyní považovány za nástupce současných systémů v oficiálních strategických plánech USA (NSTIC) či EU (ENISA). Část požadovaných funkcí je již podporována existujícími kryptografickými koncepty jako jsou U-Prove či idemix. V současné době však není známý systém, který by poskytoval všechny potřebné funkce na ochranu digitální identity a zároveň byl prakticky implementovatelný na zařízeních, jako jsou čipové karty. Mezi klíčové slabiny současných systémů patří především chybějící nespojitelnost relací a absence revokace. Není tak možné efektivně zneplatnit zaniklé uživatele, ztracené či ukradené autentizační karty či karty škodlivých uživatelů. Z těchto důvodů je v této práci navrženo kryptografické schéma, které řeší slabiny nalezené při analýze existujících řešení. Výsledné schéma, jehož návrh je založen na ověřených primitivech, jako jsou $\Sigma$-protokoly pro důkazy znalostí, kryptografické závazky či ověřitelné šifrování, pak podporuje všechny požadované vlastnosti pro ochranu soukromí a digitální identity. Zároveň je však návrh snadno implementovatelný v prostředí smart-karet. Tato práce obsahuje plný kryptografický návrh systému, formální ověření klíčových vlastností, matematický model schématu v programu Mathematica pro ověření funkčnosti a výsledky experimentální implementace v prostředí .NET smart-karet. I přesto, že navrhovaný systém obsahuje podporu všech funkcí na ochranu soukromí, včetně těch, které chybí u existujících systémů, jeho výpočetní složitost zůstává stejná či nižší, doba ověření uživatele je tedy kratší než u existujících systémů. Výsledkem je schéma, které může velmi znatelně zvýšit ochranu soukromí uživatelů při jejich ověřování, především při využití v elektronických dokladech, přístupových systémech či Internetových službách.

>Magister Scientiae - MSc / The recent years have seen an increase in the number of users accessing online services using communication devices such as computers, mobile phones and cards based credentials such as credit cards. This has prompted most governments and business organizations to change the way they do business and manage their identity information. The coming of the online services has however made most Internet users vulnerable to identity fraud and theft. This has resulted in a subsequent increase in the number of reported cases of identity theft and fraud, which is on the increase and costing the global industry excessive amounts. Today with more powerful and effective technologies such as artificial intelligence, wireless communication, mobile storage devices and biometrics, it should be possible to come up with a more effective multi-modal authentication system to help reduce the cases of identity fraud and theft. A multi-modal digital identity management system IS proposed as a solution for managing digital identity information in an effort to reduce the cases of identity fraud and theft seen on most online services today. The proposed system thus uses technologies such as artificial intelligence and biometrics on the current unsecured networks to maintain the security and privacy of users and service providers in a transparent, reliable and efficient way. In order to be authenticated in the proposed multi-modal authentication system, a user is required to submit more than one credential attribute. An artificial intelligent technology is used to implement a technique of information fusion to combine the user's credential attributes for optimum recognition. The information fusion engine is then used to implement the required multi-modal authentication system.

In this dissertation, I analyze online environmental anti-toxics activism. Environmental activist groups have created a presence on the World Wide Web to help empower people to become aware of and struggle against pollution. The sites that I explore (http://www.epa.gov/tri/, http://www.epa.gov/enviro/wme/, http://www.rtknet.org/, and http://www.scorecard.org/) serve as devices of this empowerment and by extension recruit people to the political goals of anti-toxics activism. In my analysis, I focus on a series of questions germane to this context. How can/does this movement go online and utilize that presence to sway others to their cause and ideology? How then is that cause represented digitally, in the online medium? What are the reciprocal impacts of that representation on the movement itself? Most importantly, what form of activist identity is being promoted through the mediation of the online interface? That is, how are the identity of the self as activist and the related understanding of space and place altered through their translation into a digital environment? What are the parameters and limitations of digitally mediated, informed empowerment? I undertake to critique empowerment as found through the digital translation of environmental anti-toxics activism into the virtual space of the Web. I show that particular uses of this Internet application invent (reinvent/reinforce) versions of environmental anti-toxics activism, digitized versions which must be understood in terms of their wider assumptions and implications. I break the study into three main parts. The first part lays theoretical groundwork for studying Web-based entities. The second part deals with more particular foundational elements for digital environmental anti-toxics activism, especially in terms of information. In the final section, I analyze and critique the forms of digital identity and empowerment that the websites create. I conclude that digital empowerment, defined primarily through access to expert information, actually represents an impoverished version of empowerment which may do little to aid real-world toxic struggles. / Ph. D.

Diploma thesis 77 million PlayStation Network accounts stolen, does it affect us?: An analysis of Internet discussions revolving around this topic deals with the case of what so far seems to be the biggest case of user information leak on the Internet. The introduction outlines the history and development of PlayStation consoles and maps major attempts to jailbreak the last generation of the console by hackers. The following section presents PlayStation Network itself, whose users were at risk of the loss of their online identity because of the attack and chronologically describes the course of breach-related events including the subsequent theft of user data. It also focuses in detail on the case of GeoHot - a hacker whose dispute with Sony alienated fellow hacker community and initiated retaliatory activities which as a result led to loss of data. Another part of the thesis examines the issue of digital identity and its protection, gives an insight into the history of the formation of the hacker community and further explains the phenomenon of existence and perception of the term hacker in the context of the Internet. The final section is devoted to analysis of selected discussion posts under thematically relevant articles, analyzes them in terms of content relevance, information sentiment and...

Un des aspects les plus intéressants des identités numériques du type "Me-Sphere" est sa variabilité : les usagers d’Internet utilisent les technologies de l’écriture et de l’image, les espaces privés/publiques des RS et les dispositifs de connectivité à Internet afin de transformer leurs identités numériques. Nous explorons ce développement hypermédiatisé de la Digital Identity. Notre hypothèse de recherche est : l’hypermédiatisation reconfigure les manières de produire et de percevoir des informations et des connaissances. Cela signifie que la production de contenus d'information a des implications logiques, esthétiques et éthiques liées à la pratique social de l'identité numérique. Mots-clés : Identité numérique (Digital ID), Réseaux socionumériques (RS), Interaction, Hypermédiatisation, Me-Sphere / One of the most interesting aspects of "Me-Sphere" digital identities is their variability: (a) Internet users employ the technologies of writing and images, (b) private/public areas of social network, and (c) connectivity devices of Internet, to transform their digital identities. We explore this hyper-mediatized development of Personal Identity. Our research hypothesis is: the hyper-mediatization reconfigures the production and information of knowledge. This means that the production of information contents has logical, aesthetic and ethical implications on the social practice of digital identity. Keywords Digital identity (digital ID), Social Networks (RS), Interaction, Hyper-mediatization, Me-Sphere

La thèse porte sur les usages sociopolitiques de l’actualité en ligne par les profanes sur Facebook. Initialement conçu pour l’échange privé, ce réseau social est également devenu un espace pour s’informer, partager et commenter les nouvelles. Ces pratiques sont analysées à partir de trois entrées : les spécificités du dispositif technique, le rapport au politique des participants et, enfin, le rôle du genre dans les prises de parole sur Facebook. Ce travail se fonde sur l’analyse comparée de la participation sur une sélection de pages Facebook de médias et de profils personnels sur ce réseau. La méthodologie repose sur une observation ethnographique en ligne et sur une enquête qualitative par entretiens.Les principaux résultats démontrent que les actualités politiques débouchent sur des réactions davantage fondées sur l’émotion que sur la rationalité et sur des affrontements de camps d’opinion. Ces débats se déroulent essentiellement sur les pages publiques des médias alors que les Timelines sont plutôt des espaces de diffusion et de partage d’actualités. Les femmes manifestent autant que les hommes un intérêt pour les questions publiques et Facebook est un espace commun d’indignation. En dépit d’opinions affirmées, les modes d’interaction des participantes sont plutôt modérés à l’inverse de ceux des hommes, plus investis dans des confrontations. Si Facebook contribue, en un sens, à un élargissement de l’espace public, la participation étudiée demeure limitée et ne s’apparente pas à des débats susceptibles de revivifier la démocratie. / The thesis focuses on the socio-political uses of online news for laymen, specifically on Facebook. Originally designed for the private exchange, this social network has also become a place to access, share and comment the news. These practices are analysed through three inputs: the specifics of the technical device, the relation to politics by participants, and, finally, the role of gender in speaking out on Facebook.This work is based on a comparative analysis of participation around political events on selected Facebook media pages and on personal profiles of the social network. The methodology is based on an online ethnographic observation and on qualitative interviews.The main results show that political events lead to reactions based more on emotion than on rationality and on opinion camps clashes. These debates mainly take place on the media public pages while the timelines are rather dissemination areas, by sharing news. Women manifest as much as men their interest for public issues and Facebook is a common area to express indignation. Despite asserted opinions, women get involved in more moderate forms of interaction unlike men who are more invested in conflictual exchanges. In a sense, if Facebook contributes to an extension of the public space, participation remains limited and does not akin to discussions that are likely to revive democracy.

The advent of social media has witnessed a transformation in how audiences interact with marketers online. While previous research has shown that media consumers generally hold a negative view of advertising, today’s media consumers are engaging with brands more than ever. This study examines what it means to be an active fan of marketers in social media to the modern media consumer through an investigation of how audiences relate to brands in the social media space. Centered around audiences’ uses and gratifications of three successful brand communities within Facebook through qualitative (field observations and individual interviews) and quantitative (surveys) methods, this study intends to gain further knowledge about the role of social media and its impact on forming new cultural trends. The findings suggest that while the uses and gratifications of Facebook brand pages and what becoming a fan of a brand on Facebook signifies to social media users vary, the prevailing motivation for and function of brand community membership is the construction of one’s digital identity in association with the brands of one’s choosing. Furthermore, despite being aware that Facebook brand communities are marketing platforms, fans were largely receptive to and held a positive attitude towards the brands. This critical study of brand fans on Facebook presents the importance of studying social media’s uses and implications in order to better understand new audience cultures within the interactive media landscape.

Anonymous signatures pose a significant threat to the legitimacy of the online petition as a persuasive form of political communication. While anonymous signatures address some privacy concerns for online petitioners, they often fail to identify petitioners as numerically distinct and socially relevant persons, Since anonymous signatures often fail to personally identify online petitioners, they often fail to provide sufficient reason for targeted political authorities to review and respond to their grievances. To recover the personal rhetoric of the online petition in a way that strikes a balance between the publicity and privacy concerns of petitioners, we should reformat online petitions as pseudonymous social networks of personal testimony between petitioners and targeted political authorities. To this end, the pseudonymous signatures of online petitions should incorporate social frames, co-authored complaints and demands, multimedia voice, and revisable support.

La recherche porte sur une étude théorique des réseaux sociaux numériques dans l'état actuel des connaissances. La problématique est discutée en s’appuyant sur un large panel d’auteurs et de pensées allant des années soixante-dix jusqu’à nos jours. En effet, les réseaux sociaux qui sont passés de startup à multinationales au cours des années deux-mille ont radicalement changé le paysage des médias et de la communication entre les individus. À partir de ce constat, nous pouvons nous demander si l'utilisation des réseaux sociaux influence directement les constructions identitaires et sociales des adolescents ? En outre, cette étude démontre comment les identités fabriquées en ligne constituent par la suite, un facteur prépondérant dans la représentation sociale et identitaire des jeunes. L’élève adapte ses identités et ses datas au sein de ses espaces numériques par la réception faite, puis acquise des innovations techniques. Les données recueillies auprès des élèves et les hypothèses formulées dégagent des perspectives futures. En effet, les connaissances numériques du fait religieux circulant sur internet constituent un élément important dans la construction identitaire des élèves. C’est dans les espaces numériques que les élèves développent les datas identités. Premièrement de manière active par l’usage des réseaux sociaux numériques, puis de manière passive à travers les cookies et les recommandations par algorithme. Le rôle grandissant d’Internet dans le processus identitaire, avec l’usage massif des réseaux sociaux et des applications numériques de mieux en mieux maitrisées par les élèves, soulève un certain nombre d’enjeux éducatifs et pédagogiques. Autrement dit les enjeux et défis pour l’Éducation Nationale s’articulent autour de l’usage in situ et ex situ des espaces numériques. / Through a theoritical study of social and digital media, this reseacrh work introduces first, the knowledge produced so far, on it. This work is based on a wide range of authors and thoughts from the seventies till today’s ones, in order to discuss the main issue. Indeed, the social media that turned from startup to multinational companies throughout the years 2000’s, have dramatically changed the landscape of media and communication among individuals. Starting from this observation, one has to ask the question of whether social media, has a direct influence on teenagers’ identity and social construction. This study demonstrates in fact, how Online identities are made thereafter, a key factor of youths’ social and identity representation. The student adapts his identity and his data within his digital spaces according to the reception produced and then acquired of the devices innovations. By framing the collected data from students within the assumed assumptions frame, future prospects are made out. As a matter of a fact, digital knowledge of the religious fact circulating on Internet, is an important element in the identity construction of students. It is in digital spaces that students develop the data identities. First they do it actively through the use of social and digital media, then passively through cookies and recommendations made by algorithm. The growing role of Internet in the identity process, with the massive use of social and digital media applications better mastered by students, raises a number of educational and pedagogical issues. In other words, the challenges and what is at stake for the French National Education, revolves about the use in situ and ex situ of the digital spaces.