This dissertation investigated online aggression in emerging adults to understand the contextual power of anonymity and social modeling. Emerging adults are characterized as undergoing a period of identity exploration, instability, self-focus, transition, and possibility (Arnett, 2004). Given the importance of identity development at this stage of the lifespan, this research explored religiosity/spirituality and political ideology; two pivotal belief systems that are introspectively evaluated and molded in emerging adults as they separate their identities from their world views (Barry & Nelson, 2004). Furthermore, this dissertation sought to apply religiosity/spirituality and political ideology to the previously established link of anonymity and social modeling and their joined impact on online aggression (Zimmerman & Ybarra, 2016). Behavioral temptation to aggress and participant responses following interaction on a mock blog was recorded and analyzed in situations of anonymity and positive or neutral social models. Aggressive social modeling influenced blog posts and behavioral temptation to aggress. Religiosity/spirituality and political attitudes moderated aggression in blog posts.

<p>Med internet som verktyg kan vi kommunicera med människor trots stora avstånd och trots att vi inte möts ansikte mot ansikte. Många nätanvändare väljer att vara anonyma gentemot varandra på nätet, på grund av försiktighet. Andra väljer att efter hand avslöja sin identitet för nätvännerna och så småningom ta med sig nätrelationen in i vardagslivet utanför internet. Syftet med denna studie är att undersöka och förklara hur nätanvändare upplever anonymitet och att inte synas för varandra.</p><p>För nätanvändare kan anonymiteten innebära en möjlighet att befria sig från det sociala livets krav och visa mer av sitt rätta jag inför nätvännerna, eftersom det på nätet är möjligt att hitta likasinnade och andra som accepterar mig som jag är, oavsett vem jag är. Anonymiteten kan också innebära att nätanvändaren av försiktighet avstår från djupare relationer på nätet. Om detta vittnar ett flertal av respondenterna i denna studie, som bygger på en enkät på internet hösten 2005. 208 svarade på enkäten och drygt en fjärdedel av dessa har på något sätt reflekterat över fenomenet anonymitet och att inte synas för varandra i sociala relationer på nätet. Metoden är kvalitativ då resultatet utgår från enkätens öppna frågor, med möjlighet till berättande svar.</p><p>I reflektionerna ingår tankar kring den kroppslöshet, eller befrielse från tid och rum, som internet medger. Här kan kommunikation ske på distans oberoende av både tid och plats, liksom också i realtid men utan att ses. Då spelar det ingen roll hur jag ser ut, vilka kläder jag har eller andra yttre faktorer som kan påverka motpartens syn på mig. Ålder, kön, socioekonomiska eller sociokulturella faktorer spelar heller ingen roll.</p><p>Mina slutsatser i denna studie är att den bokstavliga och bildliga anonymiteten på nätet kan vara antingen befriande eller begränsande för nätanvändaren; befriande för den som använder nätet för självförverkligande och reflexivt identitetsbyggande; begränsande för den som av försiktighet inte tillåter sig att utveckla nära och djupa sociala relationer på nätet på grund av anonymiteten.</p> / <p>Using the net for relational purposes is becoming a growing trend; net surfers make friends online. This study, by Eva Johansson, shows that the net users who use the net for relational purpose can form meaningful and sustainable social relations with other net users whom they have never met in real life (IRL), and may never meet face to face.</p><p>The purpose of this study is to find out how the possible anonymity and the lack of meeting face to face effect relations on the net. 208 net users have answered a survey about social relations on the net. The answers in this mainly qualitative study gives a hint that anonymity can be both limiting and liberating for the user. Limiting for those who are cautious and therefore do not form deep emotional relationships on the net; and liberating for those who, through anonymity, can express their true selves to strangers on the net. The disembodiment of the net is also a liberating factor.</p><p>A majority of the respondents are women and many of them are middle aged. They have a considerable skill and experience as net users, and do use the net for their own purposes.</p>

<p>Internet and mobile communications have had a profound effect on today’s society. New services are constantly being deployed, in which an increasing amount of personal data is being processed in return for personally tailored services. Further, the use of electronic surveillance is increasing. There is the risk that honest citizens will have their privacy invaded for “the greater good”. We argue that it is of uttermost importance to retain the individuals’ control over their personal spheres.</p><p>One approach for enhancing the users’ privacy is to deploy technical measures for safeguarding privacy, so-called Privacy-Enhancing Technologies (PETs). This thesis examines a set of PETs for enabling anonymous communication, so-called anonymous overlay networks,which eliminate the processing of personal data altogether by allowing the users act anonymously when communicating in a networked environment.</p><p>This thesis focuses mainly on mobile networks. These are of great interest because on the one hand they lay the groundwork for new innovative applications, but on the other hand they pose numerous novel challenges to privacy. This thesis describes the implementation</p><p>and performance evaluation of mCrowds – an anonymous overlay network for mobile Internet that enables anonymous browsing. It also describes the ongoing investigation on how to design anonymous overlay networks in order to make them suitable for mobile ad hoc</p><p>networks, a required building block for ambient intelligence.</p>

Le marché dans lequel évoluent les bourses est devenu extrêmement concurrentiel, ce qui se traduit notamment par de nombreux mouvements de rapprochement ou de fusion. Dans ce contexte, les bourses cherchent à tout moment à améliorer la qualité du système de marché qu'elles proposent à leurs clients. La microstructure des marchés est le domaine de la finance qui étudie le lien entre organisation et qualité des marchés, et deux problématiques précises de microstructure sont traitées dans cette thèse. En matière d'asymétrie d'information, nous comparons différents modèles de décomposition de la fourchette de prix appliqués à un marché dirigé par les ordres, et proposons une recommandation quant aux modèles susceptibles de fournir les meilleurs résultats. En matière de transparence des marchés, nous commençons par fournir une revue détaillée de la littérature, avant d'analyser la question de l'anonymat pré-transactionnel selon deux méthodes : une analyse empirique du passage à l'anonymat sur Euronext Paris en avril 2001, et une étude expérimentale. Nos résultats concluent à une absence d'effet de l'anonymat sur l'asymétrie d'information, l'efficience et la liquidité, ce qui contredit d'autres résultats de la littérature. Notre analyse empirique émet aussi l'hypothèse de l'existence d'un facteur de liquidité globale, dont la prise en compte est sans doute fondamentale dans les études portant sur l'évolution de la liquidité sur les marchés./The market for financial markets has become increasingly competitive, and this leads to strategic moves such as mergers or acquisitions. In this context, stock exchanges struggle to offer the best quality system to their customers. The link between the organization of markets and their quality is one of the central themes of the research area called market microstructure. This dissertation focuses on two key aspects of microstructure research. In terms of information asymmetry, we compare the results provided by several spread decomposition models that are applied to order-driven markets, and we make a recommendation on the models that provide the best estimates. On the issue of transparency, we first review the literature and then provide two analyses of the impact of pre-trade anonymity: (i) we empirically study how the switch to anonymity in Paris in April 2001 affected market quality, and (ii) we use the experimental method to assess the consequences of disclosing the ID codes of traders in an electronic order book. Our results point to the absence of an effect due to anonymity, which is at odds with existing results in the literature. Our empirical analysis also highlights the possible existence of a “global liquidity factor”, that should ideally be taken into account when studying the evolution of liquidity on financial markets.

Has it ever occurred to you to wonder why a soldier would sacrifice his life by jumping on a bomb to save the rest of his brigade? Or why an individual in a gang might display respectable behavior when alone but swear and vandalize when in the group? The phenomenon of people getting pulled into crowds and adopting the group’s mentalities and behaviors has been recognized but not fully researched. However, it has been recorded in early literature and research that it is human nature to want to fit into a group, for example in Abraham Maslow’s (1943) paper, A Theory of Human Motivation, in which he proposed that the hierarchy of human needs includes a stage that emphasized an individual’s need to feel a sense of belonging.

Durante la última década, el dominio digital se convirtió en una parte integral de nuestra vida cotidiana. Hoy en día, la transición que experimentábamos anteriormente mudando de los espacios actuales de comunicación al ciberespacio, cuando Internet era una novedad en nuestras vidas, ya no es aplicable, pasamos de uno al otro con la facilidad de pasar de una habitación a otra. En este contexto, conocimos la arquitectura participativa de la Web 2.0 y el concepto de las redes sociales online, y poco a poco, hemos pasado de la invisibilidad del ciberespacio a la super-visibilidad que tenemos hoy en día. Con todos estos factores en juego, nuestras formas de definir, entender y construir nuestras identidades han cambiado considerablemente.

Topics within small-group communication have been explored in many contexts, such as work group, organizational meeting, or online network. This area of discipline is considered crucial because this type of communication assimilates interpersonal relations within a social setting. Two elements that largely affect small-group communication dynamics are anonymity and social identity. This research invokes previous research in anonymity and social identity within small-group communication pertaining to the level of agreement and the level of group attraction through a series of experiments. Anonymity in small-group communication context is defined as a condition where the group members are not identifiable. To create anonymity among group members, this study utilized the benefit of a chat room in computer-mediated communication (CMC), which allows group members to participate in group discussion anonymously without the fear of being judged. It is argued that groups communicating synchronously via CMC would have a higher agreement than those communicating face-to-face (FtF) because the anonymity in CMC eliminates all of visual cues and therefore, unites all group members. It is also argued that members in groups in FtF are more likely to be interpersonally attracted than those in CMC. Thus, members communicating via FtF would have larger cumulative group attraction than those in CMC. Meanwhile, social identity in small-group communication context is defined as the tendency of a group member to associate with fellow members who share similarities with him or her and hold prejudice against members who are different than him or her. The element of social identity that was being activated in this study was the gender identity. This was done through using a gender-related case, an opinion scale, and distributing participants into groups of different gender compositions. It is argued that single-gender groups would have higher level of agreement and group attraction than mixed-gender groups. The experiment assigned participants into six different groups. The groups communicated via FtF or via CMC. In each setting, there were male-only groups, female-only groups, and mixed-gender groups. The only statistically significant result from the experiments suggested that in CMC, female-only groups had a higher level of agreement than mixed-gender groups. However, there were also differences of mean agreement between female-only groups in FtF and female only groups in CMC. Those communicating via CMC had higher agreement. In terms of level of group attraction, there was not any significant result in any condition. This finding suggests that in CMC, groups that are exclusively females are more conducive than other gender compositions in reaching agreement. Meanwhile, the lack of significance in group attraction between FtF and CMC suggests that people have become more familiar with anonymous CMC settings allowing them to substitute the available textual cues for visual cues.

Med internet som verktyg kan vi kommunicera med människor trots stora avstånd och trots att vi inte möts ansikte mot ansikte. Många nätanvändare väljer att vara anonyma gentemot varandra på nätet, på grund av försiktighet. Andra väljer att efter hand avslöja sin identitet för nätvännerna och så småningom ta med sig nätrelationen in i vardagslivet utanför internet. Syftet med denna studie är att undersöka och förklara hur nätanvändare upplever anonymitet och att inte synas för varandra. För nätanvändare kan anonymiteten innebära en möjlighet att befria sig från det sociala livets krav och visa mer av sitt rätta jag inför nätvännerna, eftersom det på nätet är möjligt att hitta likasinnade och andra som accepterar mig som jag är, oavsett vem jag är. Anonymiteten kan också innebära att nätanvändaren av försiktighet avstår från djupare relationer på nätet. Om detta vittnar ett flertal av respondenterna i denna studie, som bygger på en enkät på internet hösten 2005. 208 svarade på enkäten och drygt en fjärdedel av dessa har på något sätt reflekterat över fenomenet anonymitet och att inte synas för varandra i sociala relationer på nätet. Metoden är kvalitativ då resultatet utgår från enkätens öppna frågor, med möjlighet till berättande svar. I reflektionerna ingår tankar kring den kroppslöshet, eller befrielse från tid och rum, som internet medger. Här kan kommunikation ske på distans oberoende av både tid och plats, liksom också i realtid men utan att ses. Då spelar det ingen roll hur jag ser ut, vilka kläder jag har eller andra yttre faktorer som kan påverka motpartens syn på mig. Ålder, kön, socioekonomiska eller sociokulturella faktorer spelar heller ingen roll. Mina slutsatser i denna studie är att den bokstavliga och bildliga anonymiteten på nätet kan vara antingen befriande eller begränsande för nätanvändaren; befriande för den som använder nätet för självförverkligande och reflexivt identitetsbyggande; begränsande för den som av försiktighet inte tillåter sig att utveckla nära och djupa sociala relationer på nätet på grund av anonymiteten. / Using the net for relational purposes is becoming a growing trend; net surfers make friends online. This study, by Eva Johansson, shows that the net users who use the net for relational purpose can form meaningful and sustainable social relations with other net users whom they have never met in real life (IRL), and may never meet face to face. The purpose of this study is to find out how the possible anonymity and the lack of meeting face to face effect relations on the net. 208 net users have answered a survey about social relations on the net. The answers in this mainly qualitative study gives a hint that anonymity can be both limiting and liberating for the user. Limiting for those who are cautious and therefore do not form deep emotional relationships on the net; and liberating for those who, through anonymity, can express their true selves to strangers on the net. The disembodiment of the net is also a liberating factor. A majority of the respondents are women and many of them are middle aged. They have a considerable skill and experience as net users, and do use the net for their own purposes.

Mobile communication is very mature today due to the powerful computation and communication capabilities of mobile devices, the flourishing of mobile networks, the popularity of electronic commerce, and the completeness of e-payment mechanisms. It is a pleasure for mobile users to roam around the mobile networks and enjoy the mobile network services. However, there are a lot of security threats in the mobile networks, and thus we need an anonymous mutual authentication and key exchange scheme to guarantee the security and privacy for mobile users in the networks. A payment protocol is also required for charging the mobile users after using the mobile services. However, the existing payment schemes do not support anonymity and credit-based chargeability at the same time. In this dissertation, we propose a secure authentication scheme such that the mobile users can be anonymously authenticated by the system and the system can still make correct charge to these anonymous mobile users via a credit-based way simultaneously. We also propose a novel e-cash scheme which can support each mobile user to withdraw a generic e-cash and decide to spend it as an on-line e-cash or an off-line e-cash according to the payment requirement of the anonymous authentication scheme. Our proposed schemes are convenient and flexible for the mobile users, the system operator, and the bank. Besides, full privacy can be achieved for mobile users owing to the combination of our proposed schemes, which can be performed in current mobile devices efficiently with few battery energy consumptions. Furthermore, we provide anonymity control, no swindling, tamper resistance, secure mutual authentication, secure key exchange, and secure forward secrecy in the proposed anonymous authentication scheme and the e-cash scheme, where these security features are demonstrated by formal security models and theoretical proofs.

Information exchange in wireless communication without being blocked by terrain or infrastructure is easier and simpler than that in the traditional wired communication environments. Due to the transmission type, anonymity is urgently required in wireless communications for concealing the footprint of mobile users. Additionally, the mobility of a mobile device may incur possible threats to the past encrypted transmitted data, where the past session keys for the encryptions of wireless communications may be derived by the long-term secret stored the mobile device if it is lost. In this thesis, we propose an efficient solution by using symmetry-based cryptosystems for forward secrecy and anonymity in the standards of mobile networks, such as GSM, UMTS, and LTE, without losing the compatibility. By adopting secret chain (SC) based mechanism, the generation of every session key involves a short-term secret, changed in every session, to achieve forward secrecy and anonymity. Furthermore, synchronization mechanism required for the SC-protocol is also proposed. For more advanced security requirements of truly non-repudiation and strong anonymity, which is additionally anonymous to systems, certificateless signatures and group signatures are applied in the authentication protocols for UMTS and VANETs. Certificateless signatures can eliminate the overhead of using public-key infrastructure (PKI) in wireless communications. Our work proposed a certificateless signature scheme achieving the same security level of non-repudiation as that in the PKI-based signature scheme, that most of the proposed certificateless signatures cannot fulfill. Group signatures practice the privacy of the participants of the authentication protocol by originating the group signatures belonging to their group. However, directly applying group signatures in wireless communications results in inefficiency of computation when a group has a large amount of members. Therefore, we aim at reducing the computation costs of membership revocation on the proposed group signature scheme to constant without being influenced by the amount of members and then apply the scheme to VANETs and UMTS. Eventually, all the proposed schemes in the thesis are theoretically proven secure under the standard reduction.