Abstract This essay deals with the creation and usage of nicknames in synchronous CMC. Nicknames from four different IRC chat conversations related to three different topic groups have been examined. The method draws on Bechar-Israeli’s (1996) categorisation of nicknames, which has been adapted to suit the type of data sampled. Three research questions have been posed, which, in view of other studies related to this field of research (e.g. Ellison et al. 2006, Scheidt 2001, Chester & Gwynne 1998, etc.) have been examined to obtain information about the degree of anonymity and the topic-relatedness of nicknames used in chatrooms. The results show that users participating in synchronous CMC indeed follow topic-related rules for self-presentation and that anonymity has varying importance in different chatrooms.

Anonymity of shareholders and the associated degree of transparency of the joint- stock company belongs in the field of company law among the most debated issues. Especially in light of the necessary fight againstmoney laundering and financing of global terrorism European legislaton creates extensive modification of the terms which are targeted on uncovering the identity of genuine owners of joint-stock companies. Czech Republic is obliged to transpose these terms into czech law. From this perspective, it is a very dynamic subject that is rapidly evolving and is not analyzed comprehensively. Work is primarily devoted to the description of the institutes in czech private law, which allow to maintain the anonymity of shareholders and degree of their possible identification. The thesis contains also the characteristics of selected public law acts in which is presented strong public interest on the identification of beneficial owners of corporations. The thesis also reflects upcoming changes that will in the near future modify the position of shareholders and their potential unfolding. The first two chapters focus on the brief description of the historical development of the concept of shareholders anonymity and the terms of their identification. The second chapterfocuses on the enactment of theBearer...

In this age when information technologies became inseparable parts of our lives we can hardly imagine for example living without internet. There is a phenomenon connected with internet and that is large scale collection of data about internet users and their activities. Because of this fact, it is important to protect our internet privacy as a very important aspect of our lives. This work examines large scale collection of data about users internet activities. During this work, different methods and reasons for this largescale data collection are examined. Later, different ways how internet users are protected by law or how they can protect themselves are examined. One of the ways how internet users can protect their internet privacy is by using so-called anonymizing networks connected with a phenomenon called Darknet. This work examines if it is possible by ordinary internet users to adapt this method of internet privacy protection.

In ad hoc networks every device is responsible for its own basic computer services, including packet routing, data forwarding, security, and privacy. Most of the protocols used in wired networks are not suitable for ad hoc networks, since they were designed for static environments with defined borders and highly specialized devices, such as routers, authentication servers, and firewalls. This dissertation concentrates on the achievement of privacy-friendly identifiersand anonymous communication in ad hoc networks. In particular, the objective is to offer means for better anonymous communication in such networks. Two research questions were formulated to address the objective: I. How to design proper and trusted privacy-friendly digital identifiers to beused in ad hoc network environments? II. How to provide anonymous communication in ad hoc networks and whatis the performance cost in relation to the obtained degree of anonymity? To address the first research question we studied and classified the security and privacy threats, enhancements, and requirements in ad hoc networks and analyzed the need for privacy and identification. The analysis led us to the relationship between security, identification, and anonymous communication that we refer to as the “identity-anonymity paradox”. We further identifiedthe requirements for privacy-friendly identifiers and proposed the self-certified Sybil-free pseudonyms to address such requirements. The second research question was addressed with the design and implementation of the Chameleon protocol, an anonymous communication mechanism for ad hoc networks. The performance of Chameleon was evaluated using a network simulator. The results were used to find out the trade-off between anonymity and performance in terms of the expected end-to-end delay. The solutions proposed in this dissertation are important steps towards the achievement of better anonymous communications in ad hoc networks andcomplement other mechanisms required to prevent leaks of personal data.

Abstract This dissertation investigates authentication techniques in some emerging areas. Specifically, authentication schemes have been proposed that are well-suited for embedded systems, and privacy-respecting pay Web sites. With embedded systems, a person could own several devices which are capable of communication and interaction, but these devices use embedded processors whose computational capabilities are limited as compared to desktop computers. Examples of this scenario include entertainment devices or appliances owned by a consumer, multiple control and sensor systems in an automobile or airplane, and environmental controls in a building. An efficient public key cryptosystem has been devised, which provides a complete solution to an embedded system, including protocols for authentication, authenticated key exchange, encryption, and revocation. The new construction is especially suitable for the devices with constrained computing capabilities and resources. Compared with other available authentication schemes, such as X.509, identity-based encryption, etc, the new construction provides unique features such as simplicity, efficiency, forward secrecy, and an efficient re-keying mechanism. In the application scenario for a pay Web site, users may be sensitive about their privacy, and do not wish their behaviors to be tracked by Web sites. Thus, an anonymous authentication scheme is desirable in this case. That is, a user can prove his/her authenticity without revealing his/her identity. On the other hand, the Web site owner would like to prevent a bunch of users from sharing a single subscription while hiding behind user anonymity. The Web site should be able to detect these possible malicious behaviors, and exclude corrupted users from future service. This dissertation extensively discusses anonymous authentication techniques, such as group signature, direct anonymous attestation, and traceable signature. Three anonymous authentication schemes have been proposed, which include a group signature scheme with signature claiming and variable linkability, a scheme for direct anonymous attestation in trusted computing platforms with sign and verify protocols nearly seven times more efficient than the current solution, and a state-of-the-art traceable signature scheme with support for variable anonymity. These three schemes greatly advance research in the area of anonymous authentication. The authentication techniques presented in this dissertation are based on common mathematical and cryptographical foundations, sharing similar security assumptions. We call them flexible digital authentication schemes.

The current state of the industry’s methods of collecting background data reflecting diagnostic and usage information are often opaque and require users to place a lot of trust in the entity receiving the data. For vendors, having a centralized database of potentially sensitive data is a privacy protection headache and a potential liability should a breach of that database occur. Unfortunately, high profile privacy failures are not uncommon, so many individuals and companies are understandably skeptical and choose not to contribute any information. It is a shame, since the data could be used for improving reliability, or getting stronger security, or for valuable academic research into real-world usage patterns. We propose, implement and evaluate a framework for non-realtime anonymous data collection, aggregation for analysis, and feedback. Departing from the usual “trusted core” approach, we aim to maintain reporters’ anonymity even if the centralized part of the system is compromised. We design a peer-to-peer mix network and its protocol that are tuned to the properties of background diagnostic traffic. Our system delivers data to a centralized repository while maintaining (i) source anonymity, (ii) privacy in transit, and (iii) the ability to provide analysis feedback back to the source. By removing the core’s ability to identify the source of data and to track users over time, we drastically reduce its attractiveness as a potential attack target and allow vendors to make concrete and verifiable privacy and anonymity claims.

This dissertation focuses on va-rious strategies of presenting identity in contemporary art and the current trend of forming its mutations and mystifications. It deals with approaches such as when the name of an artist is absent from his performance, various forms of concealment, and the subsequent detection of an artist. The term “anonymity” is not examined as its mere literal definition, but it subsequently forks into other related meanings. The introduction points at our daily meetings with anonymity, the condensation of information stemming from all spheres including the sphere of visual arts. The subject of the dissertation is explored though the influence of media operating at a given time (time-specific) and a given place (site-specific): here and now. The text primarily deals with the phenomenon of being “anonymous”. While examining this topic, the period starting with the 1990s is discussed and supplemented by examples from the history of Slovak, Czech, and international visual art with extensions to literature, music and film. It closely focuses on the following four bi-polar forms of anonymity: celebrity / anonymous artist, art groups / collective exhibitions, street art / net art, signature art / untitled art. These terms are defined and organized into dictionary entries (containing both names of artists and definitions of terms). Comprising of over two hundred words, a hybrid thematic dictionary has been produced. It consists of already existing definitions taken from the Slovak and Czech mutations of Wikipedia which are quoted with consistence with each entry. The collaboration with Wikipedia is based on subsequent addition of the author’s definitions and thus supplements it with missing information from the sphere of visual arts. The text also deals with a current trend of renaming as a symbol of a hegemonic tool of power. The terms a.k.a., name, monogram, nick, and pseudonym are explored.

In recent years, whistleblowing has lead to big headlines aroundthe world. This thesis looks at whistleblower systems, which are systems specically created for whistleblowers to submit tips anonymously. The problem is how to engineer such a system asto maximize the anonymity for the whistleblower whilst at the same time remain usable.The thesis evaluates existing implementations for the whistle-blowing problem. Eleven Swedish newspapers are evaluated for potential threats against their whistleblowing service.I suggest a new system that tries to improve on existing systems. New features includes the introduction of JavaScript cryptography to lessen the reliance of trust for a hosted server. Use of anonymous encryption and cover traffic to partially anonymize the recipient, size and timing metadata on submissions sent by the whistleblowers. I explore the implementations of these features and the viability to address threats against JavaScript integrity by use of cover traffic.The results show that JavaScript encrypted submissions are viable. The tamper detection system can provide some integrity for the JavaScript client. Cover traffic for the initial submissions to the journalists was also shown to be feasible. However, cover traffic for replies sent back-and-forth between whistleblower and journalist consumed too much data transfer and was too slow to be useful.

Intimate partner violence (IPV) impacts the lives of millions of individuals, devastating survivors, and damaging families. Many survivors are unsure of how to get help, and many have limited access to resources. In recent years, those affected by IPV have turned online for answers and support, including forums such as Reddit, to anonymously disclose their experiences. This study examined the dialogue online between survivors of violence and those who respond to their posts on Reddit. The aim is to better understand the kinds of conversations and responses that are occurring in online communities discussing IPV. Analysis of the domestic violence subreddit highlighted positive conversations focused on helping survivors as commenters offered support, advise, understanding, education, access to resources and additional information to aid survivors in receiving help.

Current data privacy-preservation models lack the ability to aid data decision makers in processing datasets for publication. The proposed algorithm allows data processors to simply provide a dataset and state their criteria to recommend an xk-anonymity approach. Additionally, the algorithm can be tailored to a preference and gives the precision range and maximum data loss associated with the recommended approach. This dissertation report outlined the research’s goal, what barriers were overcome, and the limitations of the work’s scope. It highlighted the results from each experiment conducted and how it influenced the creation of the end adaptable algorithm. The xk-anonymity model built upon two foundational privacy models, the k-anonymity and l-diversity models. Overall, this study had many takeaways on data and its power in a dataset.