Library and Tools for Server-Side DNSSEC Implementation

Tato práce se zabývá analýzou současných open source řešení pro zabezpečení DNS zón pomocí technologie DNSSEC. Na základě provedené rešerše je navržena a implementována nová knihovna pro použití na autoritativních DNS serverech. Cílem knihovny je zachovat výhody stávajících řešení a vyřešit jejich nedostatky. Součástí návrhu je i sada nástrojů pro správu politiky a klíčů. Funkčnost vytvořené knihovny je ukázána na jejím použití v serveru Knot DNS.This thesis deals with currently available open-source solutions for securing DNS zones using the DNSSEC mechanism. Based on the findings, a new DNSSEC library for an authoritative name server is designed and implemented. The aim of the library is to keep the benefits of existing solutions and to eliminate their drawbacks. Also a set of utilities to manage keys and signing policy is proposed. The functionality of the library is demonstrated by it's use in the Knot DNS server.

Experimental Investigations Of Thermal Pulsatile Boundary Layer Flow

The need to reliably analyze, predict, and control the transport of mass, momentum, and energy in turbulent boundary layers is critically important across a broad spectrum of technological applications and scientific disciplines. While there has been extensive–and continuing– research investigating laboratory-scale canonical wall-bounded flows, beyond the scope of these well-studied flows there exists a broad range of application relevant flows that are far less studied. The theme of this dissertation research is to study a non canonical flow, specifically to study coupled momentum and thermal transport in pulsatile boundary layer flows. The primary contributions of the present work are (1) the design, fabrication, and validation of a unique flow facility to study non-equilibrium boundary layer flow and (2) to use this facility to study momentum and thermal transport in pulsatile boundary layer flow over a heated wall. In pulsatile boundary layer flow, the freestream velocity has a time-steady mean component and an unsteady oscillatory component superimposed on the mean component. Pulsatile boundary layer flows are therefore periodic and unidirectional characterized by both their frequency and amplitude, and are fundamentally important in many aerodynamic, industrial, and natural flow systems. The experimental data will be analyzed through time-average and phase-average frameworks to understand the underlying flow physics of pulsatile boundary layer dynamics. Results demonstrate a varied response between the momentum and thermal field, indicating a break down in the so called Reynolds analogy assumption. The importance of buoyant transport is also demonstrated, even at low Richardson number flows

Perspectives on hypersonic viscous and nonequilibrium flow research

An attempt is made to reflect on current focuses in certain areas of hypersonic flow research by examining recent works and their issues. Aspects of viscous interaction, flow instability, and nonequilibrium aerothermodynamics pertaining to theoretical interest are focused upon. The field is a diverse one, and many exciting works may have either escaped the writer's notice or been abandoned for the sake of space. Students of hypersonic viscous flow must face the transition problems towards the two opposite ends of the Reynolds or Knudsen number range, which represents two regimes where unresolved fluid/gas dynamic problems abound. Central to the hypersonic flow studies is high-temperature physical gas dynamics; here, a number of issues on modelling the intermolecular potentials and inelastic collisions remain the obstacles to quantitative predictions. Research in combustion and scramjet propulsion will certainly be benefitted by advances in turbulent mixing and new computational fluid dynamics (CFD) strategies on multi-scaled complex reactions. Even for the sake of theoretical development, the lack of pertinent experimental data in the right energy and density ranges is believed to be among the major obstacles to progress in aerothermodynamic research for hypersonic flight. To enable laboratory simulation of nonequilibrium effects anticipated for transatmospheric flight, facilities capable of generating high enthalpy flow at density levels higher than in existing laboratories are needed (Hornung 1988). A new free-piston shock tunnel capable of realizing a test-section stagnation temperature of 10(exp 5) at Reynolds number 50 x 10(exp 6)/cm is being completed and preliminary tests has begun (H. Hornung et al. 1992). Another laboratory study worthy of note as well as theoretical support is the nonequilibrium flow experiment of iodine vapor which has low activation energies for vibrational excitation and dissociation, and can be studied in a laboratory with modest resources (Pham-Van-Diep et al. 1992)

A longitudinal study of DNS traffic: understanding current DNS practice and abuse

This thesis examines a dataset spanning 21 months, containing 3,5 billion DNS packets. Traffic on TCP and UDP port 53, was captured on a production /24 IP block. The purpose of this thesis is twofold. The first is to create an understanding of current practice and behavior within the DNS infrastructure, the second to explore current threats faced by the DNS and the various systems that implement it. This is achieved by drawing on analysis and observations from the captured data. Aspects of the operation of DNS on the greater Internet are considered in this research with reference to the observed trends in the dataset, A thorough analysis of current DNS TTL implementation is made with respect to all response traffic, as well as sections looking at observed DNS TTL values for ,za domain replies and NX DOMAIN flagged replies. This thesis found that TTL values implemented are much lower than has been recommended in previous years, and that the TTL decrease is prevalent in most, but not all EE TTL implementation. With respect to the nature of DNS operations, this thesis also concerns itself with an analysis of the geoloeation of authoritative servers for local (,za) domains, and offers further observations towards the latency generated by the choice of authoritative server location for a given ,za domain. It was found that the majority of ,za domain authoritative servers are international, which results in latency generation that is multiple times greater than observed latencies for local authoritative servers. Further analysis is done with respect to NX DOM AIN behavior captured across the dataset. These findings outlined the cost of DNS miseonfiguration as well as highlighting instances of NXDOMAIN generation through malicious practice. With respect to DNS abuses, original research with respect to long-term scanning generated as a result of amplification attack activity on the greater Internet is presented. Many instances of amplification domain scans were captured during the packet capture, and an attempt is made to correlate that activity temporally with known amplification attack reports. The final area that this thesis deals with is the relatively new field of Bitflipping and Bitsquatting, delivering results on bitflip detection and evaluation over the course of the entire dataset. The detection methodology is outlined, and the final results are compared to findings given in recent bitflip literature

Annual Research Briefs, 1990

The 1990 annual progress reports of the Research Fellows and students of the Center for Turbulent Research (CTR) are included. It is intended primarily as a contractor report to NASA, Ames Research Center. In addition, numerous CTR Manuscript Reports were published last year. The purpose of the CTR Manuscript Series is to expedite the dissemination of research results by the CTR staff. The CTR is devoted to the fundamental study of turbulent flow; its objectives are to produce advances in physical understanding of turbulence, in turbulence modeling and simulation, and in turbulence control

An Examination of E-Banking Fraud Prevention and Detection in Nigerian Banks

E-banking offers a number of advantages to financial institutions, including convenience in terms of time and money. However, criminal activities in the information age have changed the way banking operations are performed. This has made e-banking an area of interest. The growth of cybercrime – particularly hacking, identity theft, phishing, Trojans, service denial attacks and account takeover– has created several challenges for financial institutions, especially regarding how they protect their assets and prevent their customers from becoming victims of cyber fraud. These criminal activities have remained prevalent due to certain features of cyber, such as the borderless nature of the internet and the continuous growth of the computer networks. Following these identified challenges for financial institutions, this study examines e-banking fraud prevention and detection in the Nigerian banking sector; particularly the current nature, impacts, contributing factors, and prevention and detection mechanisms of e-banking fraud in Nigerian banking institutions. This study adopts mixed research methods with the aid of descriptive and inferential analysis, which comprised exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) for the quantitative data analysis, whilst thematic analysis was used for the qualitative data analysis. The theoretical framework was informed by Routine Activity Theory (RAT) and Fraud Management Lifecycle Theory (FMLT). The findings show that the factors contributing to the increase in e-banking fraud in Nigeria include ineffective banking operations, internal control issues, lack of customer awareness and bank staff training and education, inadequate infrastructure, presence of sophisticated technological tools in the hands of fraudsters, negligence of banks’ customers concerning their e-banking account devices, lack of compliance with the banking rules and regulations, and ineffective legal procedure and law enforcement. In addition, the enforcement of rules and regulations in relation to the prosecution of financial fraudsters has been passive in Nigeria. Moreover, the findings also show that the activities of each stage of fraud management lifecycle theory are interdependent and have a collective and considerable influence on combating e-banking fraud. The results of the findings confirm that routine activity theory is a real-world theoretical framework while applied to e-banking fraud. Also, from the analysis of the findings, this research offers a new model for e-banking fraud prevention and detection within the Nigerian banking sector. This new model confirms that to have perfect prevention and detection of e-banking fraud, there must be a presence of technological mechanisms, fraud monitoring, effective internal controls, customer complaints, whistle-blowing, surveillance mechanisms, staff-customer awareness and education, legal and judicial controls, institutional synergy mechanisms of in the banking systems. Finally, the findings from the analyses of this study have some significant implications; not only for academic researchers or scholars and accounting practitioners, but also for policymakers in the financial institutions and anti-fraud agencies in both the private and public sectors

Facilitation of behaviour change communication process for maternal, newborn, and child health at primary health care level of midwifey practice in Kaduna State, Nigeria.

Ph. D. University of KwaZulu-Natal, Durban 2012.Background: Nigeria’s unacceptably high maternal and child mortality rates are related, among other things, to the people’s lack of access to appropriate information to assist them in making decisions about their health, and to promote their utilization of available services. Midwives’ skills for result-oriented client education and friendly services are fundamental to women’s behaviour change for favourable maternal and child outcomes. Aim: The purpose of the study was to appraise and facilitate behaviour change communication (BCC) by midwives at primary health care level of maternal, newborn, and child care. Methods: Action research, with concurrent transformative mixed method data collection strategy, was adopted for the study, and the maximum variation sampling technique was employed to recruit participants. Fifteen, representing sixty-eight percent of the twenty-two recruited midwives continued through the three phases of the study. The diagnostic, intervention, and monitoring phases of the study were arranged in line with the objectives of the study, and each succeeding phase built on the findings of the previous one. At the diagnostic phase, the strengths and weaknesses in behaviour change communication by midwives in the facilities, and the appropriate solution to bridge the gaps were identified at a three-day search conference. At the intervention phase, a training manual was developed. A capacity building programme, made up of a training component for the midwives, and an interactive session between the government and the midwives, was designed and implemented at a three-day workshop. The monitoring phase comprised the midwives’ hands-on practice, using the developed training manual, core messages, and interpersonal communication (IPC) observation checklist for three months. The implementation of the midwives’ action plans in their respective work places was also monitored. Both qualitative and quantitative data collection and analysis methods were utilized at each phase of the study. Results: The diagnostic phase revealed that midwives lacked the essential knowledge, skills and attitudes for effective behaviour change communication activities in the facilities. Health talks were seen as midwives’ responsibility, however, they were unplanned, difficult, and given routinely, providing inadequate information, and without focus on behaviour change. Socio-cultural and environmental factors such as inadequate staff, material and time were barriers. The midwives’ knowledge, attitudes, and skills responded positively and significantly to the training, to hands-on practice, and to the use of reminders at their workplaces. In addition, midwives were able to network for support from the community and other workers in the facilities, to implement their action plans. Through exhibition of innovative behaviour in the implementation of their action plans, the midwives in most of the facilities were able to effect changes to facilitate utilization of maternal and child health (MCH) services. The gross shortage of staff, staff transfers, lack of drugs and supplies, heavy workload, and midwives’ lack of trust in their employers, however, hindered optimum implementation of some of the plans. Conclusion: The women living in the communities where the midwives worked, desired to know more about the role of midwives and to have competent ones; while the midwives were willing to assist their clients to adopt desired health and health-seeking behaviours, because they were duly recognized and empowered during the project. The study showed that the grave disconnection between the midwives and the government policies / programmes to facilitate behaviour change, and promote maternal and child health, can be corrected. The findings and recommendations have implications for practice, education, research and policymaking in Kaduna State and similar settings.Editor's declaration is on page 453