Security of communications is a major requirement for Mobile Adhoc NETworks(MANETs) since they use wireless channel for communications which can be easily tapped, and physical capture of MANET nodes is also quite easy. From the point of view of providing security in MANETs, there are basically two types of MANETs, viz., authoritarian MANETs, in which there exist one or more authorities who decide the members of the network, and self-organized MANETs, in which there is no such authority. Ensuring security of communications in the MANETs is a challenging task due to the resource constraints and infrastructure-less nature of these networks, and the limited physical security of MANET nodes. Attacks on security in a MANET can be launched by either the external attackers which are not legitimate members of the MANET or the internal attackers which are compromised members of the MANET and which can hold some valid security credentials or both. Key management and authentication protocols(KM-APs)play an important role in preventing the external attackers in a MANET. However, in order to prevent the internal attackers, an intrusion detection system(IDS) is essential. The routing protocols running in the network layer of a MANET are most vulnerable to the internal attackers, especially to the attackers which launch packet dropping attack during data packet forwarding in the MANET. For an authoritarian MANET, an arbitrated KM-AP protocol is perfectly suitable, where trusts among network members are coordinated by a trusted authority. Moreover, due to the resource constraints of a MANET, symmetric key management protocols are more efficient than the public key management protocols in authoritarian MANETs. The existing arbitrated symmetric key management protocols in MANETs, that do not use any authentication server inside the network are susceptible to identity impersonation attack during shared key establishments. On the other hand, the existing server coordinated arbitrated symmetric key management protocols in MANETs do not differentiate the role of a membership granting server(MGS) from the role of an authentication server, and so both are kept inside the network. However, keeping the MGS outside the network is more secure than keeping it inside the network for a MANET. Also, the use of a single authentication server inside the network cannot ensure robustness against authentication server compromise. In self-organized MANETs, public key management is more preferable over symmetric key management, since the distribution of public keys does not require a pre-established secure channel. The main problem for the existing self-organized public key management protocols in MANETs is associated with the use of large size certificate chains. Besides, the proactive certificate chaining based approaches require each member of a MANET to maintain an updated view of the trust graph of the entire network, which is highly resource consuming. Maintaining a hierarchy of trust relationships among members of a MANET is also problematic for the same reason. Evaluating the strength of different alternative trust chains and restricting the length of a trust chain used for public key verification is also important for enhancing the security of self-organized public key management protocols. The existing network layer IDS protocols in MANETs that try to defend against packet dropping attack use either a reputation based or an incentive based approach. The reputation based approaches are more effective against malicious principals than the incentive based approaches. The major problem associated with the existing reputation based IDS protocols is that they do not consider the protocol soundness issue in their design objectives. Besides, most of the existing protocols incorporate no mechanism to fight against colluding principals. Also, an IDS protocol in MANETs should incorporate some secure and efficient mechanism to authenticate the control packets used by it. In order to mitigate the above mentioned problems in MANETs, we have proposed new models and designed novel security protocols in this thesis that can enhance the security of communications in MANETs at lesser or comparable cost. First, in order to perform security analysis of KM-AP protocols, we have extended the well known strand space verification model to overcome some of its limitations. Second, we have proposed a model for the study of membership of principals in MANETs with a view to utilize the concept for analyzing the applicability and the performance of KM-AP protocols in different types of MANETs. Third and fourth, we have proposed two novel KM-AP protocols, SEAP and CLPKM, applicable in two different types of MANET scenarios. The SEAP protocol is an arbitrated symmetric key management protocol designed to work in an authoritarian MANET, whereas the CLPKM protocol is a self-organized public key management protocol designed for self-organized MANETs. Fifth, we have designed a novel reputation based network layer IDS protocol, named EVAACK protocol, for the detection of packet dropping misbehavior in MANETs. All of the three proposed protocols try to overcome the limitations of the existing approaches in their respective categories. We have provided rigorous mathematical proofs for the security properties of the proposed protocols. Performance of the proposed protocols have been compared with those of the other existing similar approaches using simulations in the QualNet simulator. In addition, we have also implemented the proposed SEAP and CLPKM protocols on a real MANET test bed to test their performances in real environments. The analytical, simulation and experimentation results confirm the effectiveness of the proposed schemes.

Les applications grand public comme la téléphonie mobile ou les cartes bancaires manipulent des données confidentielles. A ce titre, les circuits qui les composent font de plus en plus l'objet d'attaques qui présentent des menaces pour la sécurité des données. Les concepteurs de systèmes sur puce (SoC) doivent donc proposer des solutions sécurisées, tout en limitant le coût et la complexité globale des applications. L’analyse des attaques existantes sur les circuits numériques nous a orienté vers celles se basant sur la tension d'alimentation, dans des nœuds technologiques avancés.Dans un premier temps, nous avons déterminé la signature électrique d’un circuit en phase de conception. Pour cela, un modèle électrique a été proposé, prenant en compte la consommation en courant et la capacité de la grille d'alimentation. L'extraction de ces paramètres ainsi que l'évaluation du modèle sont présentées. L’utilisation de ce modèle a permis de mesurer la vulnérabilité d’un circuit mais aussi d’évaluer quantitativement des contremesures, notamment celle utilisant des capacités de découplage. Ensuite, l’étude se consacre à l’injection de fautes par impulsions de tension d’alimentation. Les mécanismes d’injection de fautes sur des circuits numériques ont été étudiés. Dès lors, des solutions de détection d’attaques ont été proposées et évaluées à la fois en simulation et par des tests électriques sur circuit. Les résultats ont permis de confirmer les analyses théoriques et la méthodologie utilisée.Ce travail a ainsi montré la faisabilité de solutions à bas coût contre les attaques actives et passives en tension, utilisables dans le cadre d’un développement industriel de produits. / General use products as mobile phones or smartcards manipulate confidential data. As such, the circuits composing them are more and more prone to physical attacks, which involve a threat for their security. As a result, SoC designers have to develop efficient countermeasures without increasing overall cost and complexity of the final application. The analysis of existing attacks on digital circuits leads to consider power attacks, in advanced technology nodes.First of all, the power signature of a circuit was determined at design time. To do so, an electrical model was suggested based on the current consumption and the overall power grid capacitance. The methodology to extract these parameters, as well as the evaluation of the model are presented. This model allows designers to anticipate information leakage at design time and to quantify the protection of countermeasures, as the use of integrated decoupling capacitors. Then, the study was dedicated to power glitch attacks. The different fault injection mechanisms were analyzed in details. From then on, a set of detection circuits were suggested and evaluated at design time and on silicon by electrical tests. Both the theoretical analysis and the given methodology were confirmed by the test campaigns.This work demonstrated that the design of low-cost solutions against passive and active power attacks can be achieved, and used in a large scale product development.

This diploma work characterizes and analyzes the business company. It contains method of solving problems, consequent on the analysis, solving implementation problems and it is project tools for improve future position of company on market by means of electronic market. For further, it is describe economics analysis of design e-shop and it is implementation in chosen company.

Tato diplomová práce představuje model a prototyp kooperativního distributivního systému zálohování dat založeném na P2P komunikační síti. Návrh systému umožňuje uživatelům přispět svým lokálním volným místem na disku do systému výměnou za spolehlivé úložiště jejich dat u jiných uživatelů. Představené řešení se snaží splnit požadavky uživatelů na ukládání dat, zároveň však také řeší, jak se vypořádat s mírou nepředvídatelnosti uživatelů  ohledně poskytování volného místa. To je prováděno dvěma způsoby - využitím Reed - Solomon kódů a zároveň také tím, že poskytuje možnost nastavení parametrů dostupnosti. Jedním z těchto parametrů je časový rozvrh, který značí, kdy uživatel může nabídnout předvídatelný přínos do systému. Druhý parametr se týká spolehlivosti konkrétního uživatele v rámci jeho slíbeného časového úseku. Systém je schopen najít synchronizaci ukládaných dat na základě těchto parametrů. Práce se zaměřuje rovněž na řešení zabezpečení systému proti širšímu spektru možných útoků. Hlavním cílem je publikovat koncept a prototyp. Jelikož se jedná o relativně nové řešení, je důležitá také zpětná vazba od široké veřejnosti, která může produkt používat. Právě jejich komentáře a připomínky jsou podnětem pro další vývoj systému.

Neuer WWW-Server Metacomputing - neue Aufgabenverteilung im Netz Harvest Secure Shell Nutzung der WS-Pools SW-Umgebung Parsytec URZ auf der CeBit Software-News Dienste des URZ - Ueberblick

Perspektiven im Netzbereich C.A.N. - Chemnitzer AbsolventenNetz Grafische Benutzeroberfl¨achen im Netz (VNC) PGP 5.x und GNUPG Neuigkeiten bei der Secure Shell (SSH) Vim 5.x Richtlinien zur Sicherheit im Campusnetz Ein Jahr Einsatz von Windows NT im URZ

The exponential rise in the generation of data has introduced many new areas of research including data science, data engineering, machine learning, artificial in- telligence to name a few. It has become important for any industry or organization to precisely understand and analyze the data in order to extract value out of the data. The value of the data can only be realized when it is put into practice in the real world and the most common approach to do this in the technology industry is through software engineering. This brings into picture the area of privacy oriented software engineering and thus there is a rise of data protection regulation acts such as GDPR (General Data Protection Regulation), PDPA (Personal Data Protection Act), etc. Many organizations, governments and companies who have accumulated huge amounts of data over time may conveniently use the data for increasing business value but at the same time the privacy aspects associated with the sensitivity of data especially in terms of personal information of the people can easily be circumvented while designing a software engineering model for these types of applications. Even before the software engineering phase for any data processing application, often times there can be one or many data sharing agreements or privacy policies in place. Every organization may have their own way of maintaining data privacy practices for data driven development. There is a need to generalize or categorize their approaches into tactics which could be referred by other practitioners who are trying to integrate data privacy practices into their development. This qualitative study provides an understanding of various approaches and tactics that are being practised within the industry for privacy preserving data science in software engineering, and discusses a tool for data usage monitoring to identify unethical data access. Finally, we studied strategies for secure data publishing and conducted experiments using sample data to demonstrate how these techniques can be helpful for securing private data before publishing. / Graduate

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