Automatic Verification of Transactions on an Object-Oriented Database

In the context of the object-oriented data model, a compiletime approach is given that provides for a significant reduction of the amount of run-time transaction overhead due to integrity constraint checking. The higher-order logic Isabelle theorem prover is used to automatically prove which constraints might, or might not be violated by a given transaction in a manner analogous to the one used by Sheard and Stemple (1989) for the relational data model. A prototype transaction verification tool has been implemented, which automates the semantic mappings and generates proof goals for Isabelle. Test results are discussed to illustrate the effectiveness of our approach

The Android Platform Security Model

Android is the most widely deployed end-user focused operating system. With its growing set of use cases encompassing communication, navigation, media consumption, entertainment, finance, health, and access to sensors, actuators, cameras, or microphones, its underlying security model needs to address a host of practical threats in a wide variety of scenarios while being useful to non-security experts. The model needs to strike a difficult balance between security, privacy, and usability for end users, assurances for app developers, and system performance under tight hardware constraints. While many of the underlying design principles have implicitly informed the overall system architecture, access control mechanisms, and mitigation techniques, the Android security model has previously not been formally published. This paper aims to both document the abstract model and discuss its implications. Based on a definition of the threat model and Android ecosystem context in which it operates, we analyze how the different security measures in past and current Android implementations work together to mitigate these threats. There are some special cases in applying the security model, and we discuss such deliberate deviations from the abstract model

Towards persistent resource identification with the uniform resource name

The exponential growth of the Internet, and the subsequent reliance on the resources it connects, has exposed a clear need for an Internet identifier which remains accessible over time. Such identifiers have been dubbed persistent identifiers owing to the promise of reliability they imply. Persistent naming systems exist at present, however it is the resolution of these systems into what Kunze, (2003) calls persistent actionable identifiers which is the focus of this work. Actionable identifiers can be thought of as identifiers which are accessible in a simple fashion such as through a web browser or through a specific application. This thesis identifies the Uniform Resource Name (URN) as an appropriate identification scheme for persistent resource naming. Evaluation of current URN systems finds that no practical means of global URN resolution is currently available. Two ,new approaches to URN resolution, unique in their use of the Domain Name System (DNS) are introduced. The proposed designs are assessed according to their Usability, Security and Evolution and an implementation described for an example URN namespace of language identifiers

Curating E-Mails; A life-cycle approach to the management and preservation of e-mail messages

E-mail forms the backbone of communications in many modern institutions and organisations and is a valuable type of organisational, cultural, and historical record. Successful management and preservation of valuable e-mail messages and collections is therefore vital if organisational accountability is to be achieved and historical or cultural memory retained for the future. This requires attention by all stakeholders across the entire life-cycle of the e-mail records. This instalment of the Digital Curation Manual reports on the several issues involved in managing and curating e-mail messages for both current and future use. Although there is no 'one-size-fits-all' solution, this instalment outlines a generic framework for e-mail curation and preservation, provides a summary of current approaches, and addresses the technical, organisational and cultural challenges to successful e-mail management and longer-term curation.

Coping with evolution in information systems: a database perspective

Business organisations today are faced with the complex problem of dealing with evolution in their software information systems. This effectively concerns the accommodation and facilitation of change, in terms of both changing user requirements and changing technological requirements. An approach that uses the software development life-cycle as a vehicle to study the problem of evolution is adopted. This involves the stages of requirements analysis, system specification, design, implementation, and finally operation and maintenance. The problem of evolution is one requiring proactive as well as reactive solutions for any given application domain. Measuring evolvability in conceptual models and the specification of changing requirements are considered. However, even "best designs" are limited in dealing with unanticipated evolution, and require implementation phase paradigms that can facilitate an evolution correctly (semantic integrity), efficiently (minimal disruption of services) and consistently (all affected parts are consistent following the change). These are also discussedComputingM. Sc. (Information Systems

Secure Virtualization and Multicore Platforms State-of-the-Art report

SVaM

Understanding the Requirements of Data Spaces in the Energy Sector

Data Management (DM) is crucial for maintaining the transparency, integrity, and reproducibility of research findings by systematically organizing, storing, preserving, and sharing data throughout the lifecycle of research projects in various domains. This is particularly critical in data-intensive sectors like the energy sector. This sector faces unique challenges due to the complex nature of its data, ranging from sensor readings to policy assessments. DM is important not only for effective data han- dling, maintenance, and accessibility, but it also significantly enhances the reliability and trustworthiness of scientific research. By ensuring data is findable, accessible, interoperable, and reusable (FAIR), DM supports the credibility of outcomes and enhances data sharing practices, facilitating innovation and applied research in this rapidly evolving field. In this thesis, we explored DM within the energy sector by identifying its require- ments, assessing current practices, and understanding the perspectives of profession- als in the field. Our research methodology began with a systematic literature review to collect foundational knowledge on the field’s challenges and requirements. This was followed by a survey that focused mainly on the top 10 most mentioned DM requirements to understand the current state of DM in the energy sector. We dis- covered a strong emphasis on data quality for analytical purposes and the need for systems that are scalable and capable of integrating diverse data sources. Interest- ingly, while real-time data processing was not seen as a high priority by the majority of survey respondents, those with in-depth DM expertise highlighted its importance, indicating different perceptions based on DM knowledge. Additionally, our survey showed a preference for simulation tools over graphical visualization and highlighted a significant gap in familiarity with the FAIR principles among professionals, which pointed to limited external data sharing practices. To address one of these identified needs, we introduced the ckanext-gitimport extension as a proof of concept. This ex- tension is designed to simplify the collection of metadata from external repositories. In summary, our work contributes to the understanding of DM in the energy sector by highlighting its current state, challenges, and areas for improvement. Through a combination of literature review, survey analysis, and the development of the exten- sion, we lay the groundwork for future advancements in DM practices, essential for enabling data sharing in the energy sector