Social Interaction Technologies (SIT) have broadened the horizon of communication in terms of the way people are able to communicate. It is now possible to interact with others across the world and engage in numerous activities ranging from dating to political movements, hobbies and even professions (Chigona, Chigona, Ngqokelela, & Mpofu, 2009). Adolescents and pre-adolescents especially are inclined to make use of SIT in their social lives with the most popular mode of communication, apart from email, being instant messaging (IM) (Brown, Mounts, Lamborn, & Steinberg, 1993; Bryant, Sanders-Jackson, & Smallwood, 2006; Madden & Rainie, 2003). Adolescents tend to use IM regularly as a tool to maintain relationships and girls especially, use it as a tool to socialise (Jennings & Wartella, 2004; Lenhart, Rainie, & Lewis, 2001). The mobile phone or cell phone, which is another example of an SIT-based communication, has become an established medium of technical, social and commercial communication in South Africa. It has given rise to the development and vast growth of a mobile youth culture who consider it an essential tool for communicating (Bosch, 2008). In South Africa, instant messages may be sent via mobile phone using one of two methods: MXit and the SMS (short messaging service). MXit and the SMS are considered convenient tools of communication as an ongoing conversation in the form of a text message may be maintained in the present (Yoshii, Matsuda, Habuchi, Dobashi, Iwata, & Kin, 2002).

This diploma thesis deals with creating a container for the migration components that are used on the Android operating system, how they operate and distribute, the life cycle of the container, and the ability to customize other components for this container. The work deals with the analysis of the Android operating system, existing solutions, the design of the own container and the way of distributing the components on the devices where the container is used. The next section describes the implementation of the server component that distributes components. It also deals with the implementation of container-containing library and a sample application that illustrates how it is possible to link all these elements together.

The master’s thesis describes IMS (IP Multimedia Subsystem) in terms of IMS core ele- ments (functional description, different implementation, signaling etc.) Communication protocols SIP and DIAMETER, together with SNMP protocol, which is used for collecting data are briefly described in this thesis.Thesis is also describing various IMS projects to- gether with Open IMS project, for whom was this surveillance system designed. Next part deals with architecture design of surveillance system along with management options implemented in surveillance system for users and administrators. The main part of master’s thesis deals with the description of the surveillance system for the experimental school Open IMS network and describes the remote configuration of core elements and monitoring of network traffic, together with the monitoring servers performance. The most of the data in the designed surveillance system are processed into graphs, which are regularly updated. The final part of master’s thesis describes the configuration and implementation of monitoring tools MRTG and NfSen that were used in created web based surveillance system.

The aim of this master thesis is to design and create the whiteboard application which allows to draw and share multimedia content in realtime using protocol XMPP between two users in the network environment. Application is a part of the open source IM client Kopete in KDE and operation system Linux.

This thesis deals with notification between smart phone and application server which controls intelligent home. It is focused on Android mobile platform and it is implemented for that platform. Notification service Google Cloud Messaging is used because it is not possible to directly address mobile phones from server. Based on actual position and user defined area the server is informed about moving to or from the area. The server can perform defined event automatically with these information. Implementation was tested in real system. Alpha and beta versions were regularly published.

Instant Messaging besitzt zweifelsohne eine sehr gro&szlig;e Zukunft. Es ist vergleichbar mit dem Short Message Service (SMS), der einen sehr gro&szlig;en Stellenwert im Mobilfunk hat. Neben der f&uuml;r SMS charakteristischen schnellen &Uuml;bermittlung von Textnachrichten bietet Instant Messaging weitere Vorteile: es ist f&uuml;r den Sender auf den ersten Blick ersichtlich, ob der Gespr&auml;chspartner f&uuml;r eine Kommunikation zur Verf&uuml;gung steht. Neben Textnachrichten k&ouml;nnen aber auch Informationen wie Bilder, Videos oder andere Formate &uuml;bermittelt werden. <br> <br> Auch f&uuml;r Organisationen ist ein Einsatz von Instant Messaging sehr interessant. Besonders in diesem Zusammenhang spielt die Sicherheit eine sehr wichtige Rolle. Daher besch&auml;ftigt sich diese Diplomarbeit vorrangig mit Instant Messaging-Systemen hinsichtlich der Prinzipien der Systemsicherheit wie Integrit&auml;t, Vertraulichkeit und Verf&uuml;gbarkeit. <br> <br> Ein weiterer Aspekt ist das Fehlen eines standardisierten Instant Messaging-Protokolls. Viele Anbieter von Instant Messaging-Systemen halten ihr System f&uuml;r das Beste und versuchen, soviele Kunden wie m&ouml;glich an sich zu binden. Daher befasst sich diese Diplomarbeit ebenfalls mit den verbreitetsten Instant Messaging-Systemen, um deren Vor- und Nachteile herauszukristallisieren. Im Weiteren wird die Funktionsweise der Protokolle erkl&auml;rt. <br> <br> Gerade im privaten Bereich spielen Konferenzsysteme (&quot;Chat&quot;) eine wichtige Rolle. Neben den Instant Messaging-Systemen wird auch diese M&ouml;glichkeit der Kommunikation beleuchtet. <br> <br> Diese Diplomarbeit wird vom Bundesamt f&uuml;r Sicherheit in der Informationstechnik (BSI), Referat &quot;IT-Sicherheitsmanagement und IT-Grundschutz&quot; betreut.

Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme der Fakultaet fuer Informatik der TU Chemnitz. Jabber ist eine XML basierte Instant Messaging und Präsenz-Management Lösung. Dieser Vortrag beinhaltet einen Überblick über die grundlegenden Konzepte von Instant Messaging, die Betrachtung von Jabber, als IM-Alternative, die Dienste, die auf dem Jabber-Protokoll aufbauen und das Phänomen X-Internet, als Webdienstplattform.

Workshop "Netz- und Service-Infrastrukturen" In dem Vortrag wird der Instant-Messaging-Dienst Jabber eingeführt. Neben dem Vergleich mit anderen Diensten dieser Art werden im Besonderen das Adressierungsschema, der Ablauf einer Kommunikation und das Zusammenspiel mit anderen Diensten erläutert.

The threat of government and corporate surveillance around the world, as well as the publicity surrounding major cybersecurity attacks, have increased interest in secure and private end-to-end communications. In response to this demand, numerous secure messaging applications have been developed in recent years. These applications have been welcomed and publically used not just by political activists and journalists but by everyday users as well. Most of these popular secure messaging applications are usable because they hide many of the details of how encryption is provided. The strength of the security properties of these applications relies on the authentication ceremony, wherein users validate the keys being used for encryption that is exchanged through the service providers. The validation process typically involves verifying the fingerprints of encryption keys to protect the communication from being intercepted.In this dissertation, we explore how to help users enhance the privacy of their communica- tions, with a particular focus on secure messaging applications. First, we explore whether secure messaging applications are meeting the security and privacy needs of their users, especially in countries that practice censorship and restrict civil liberties, including blocking access to social media and communication applications. Second, we studied existing popular secure messaging applications to explore how users interact with these applications and how well they are using the authentication ceremony during lab studies. Third, we applied design principles to improve the interfaces for the authentication ceremony, and also to help users find and perform the authentication ceremony faster. Forth, we applied the lessons from our interviews with participants in our user studies to help users comprehend the importance of authentication. As part of the effort, we developed an authentication ceremony using social media accounts to map key fingerprints to social features, pushing the ceremony to a more natural domain for users. We modified the Signal secure messaging application to include this social authentication ceremony and used a user study to compare this method to other common methods. We found that social authentication has some promising features, but that social media companies are too distrusted by users. Based on our results, we make several recommendations to improve the use of security and privacy features in secure messaging applications and outline areas for future work.

This research concerns exploiting knowledge of the user's environment (i.e., context information) to enrich a user's communication making it more personal, by ensuring that the user receives only relevant messages and calls in his/her current context, and to facilitate more opportunities for communication interactions with people that are in the same context and that share the same interests as this user. We describe in this licentiate thesis the concepts of context-addressed messaging and context-aware session control that enable users to: (1) send messages to others based on their context, rather than their network address and (2) to initiate, adapt, and terminate user's communication sessions based on this user's current context, respectively. These concepts address questions such as: how to discover, select, and switch to an optimal communication means to meet varying user, contextual, communication, and device resource requirements and preferences. A key to solving these problems is to create a representation of the user's context-dependent preferences and to process the user's context-dependent preferences which are part of context triggers. These context triggers can initiate a communication event upon a particular context update. Additionally, in order to provide the described context-aware communication functions, these mechanisms need timely access to the acquired (desired) context information. This in turn raises a plethora of other questions, such as how to discover sensors that provide the desired context information; how to acquire raw context data from these sensors; how to abstract, process, and model this data to become "understandable" to applications and system components; and how to distribute this context to applications that are running on different nodes.   This research is split into three different parts. The first part concerns investigating and implementing context management functions. As part of this research we propose a novel approach for context synthesis using context operators. We also propose a design architecture for context-aware middleware that mediates between the sensors and applications, and that is able to share and retrieve context from other nodes in the network. The second part of our research concerns our proposed mechanism for context-addressed messaging. To implement this mechanism we designed our own message format, called the Common Profile for Context-Addressed Messaging (CPCAM) that is able to use any high level context to compose a context-based address. Additionally, we proposed to use context-based filtering to find the correct message recipients and determine if this message is relevant to these potential message recipients in their current context, as well as to deliver this message to the recipients' preferred device that is adapted using their preferred communication means. At the end of this second part we design context-addressed messaging system operations on top of a SIP and SIMPLE-based network infrastructure. The third part of our research describes context-aware session control mechanisms using context switch and context trigger constructs. A context-switch selects an action from a set of context-dependent actions upon an incoming communication event based on the receiver's current context. In contrast, a context trigger initiates an action based on a context update and the user's preferences that are specified in this updated context. This part illustrates in several examples the context-aware session control mechanisms, i.e. the initiation of a communication session based on the match of a user's preferences and current context, as well as adaptation and (if necessary) termination of an ongoing communication session based upon the user's context-dependent preferences.   The research leading to this licentiate has created network and system level models necessary for implementation of a context-addressed communication system that would enable users to easily design their own personalized, context-aware communication services. The necessary constructs and properties of these models are designed and analyzed in the thesis, as well as in conference papers and other documents published in the process of doing the research for this thesis. A number of remaining open issues and challenges have been outlined as part of the future work. / EU FP6 MIDAS (Middleware Platform for Developing and Deploying Advanced Mobile Services) / EU FP6 MUSIC (Self-adapting Applications for Mobile Users In Ubiquitous Computing Environments)