An experiment in software reliability

The results of a software reliability experiment conducted in a controlled laboratory setting are reported. The experiment was undertaken to gather data on software failures and is one in a series of experiments being pursued by the Fault Tolerant Systems Branch of NASA Langley Research Center to find a means of credibly performing reliability evaluations of flight control software. The experiment tests a small sample of implementations of radar tracking software having ultra-reliability requirements and uses n-version programming for error detection, and repetitive run modeling for failure and fault rate estimation. The experiment results agree with those of Nagel and Skrivan in that the program error rates suggest an approximate log-linear pattern and the individual faults occurred with significantly different error rates. Additional analysis of the experimental data raises new questions concerning the phenomenon of interacting faults. This phenomenon may provide one explanation for software reliability decay

A Mobile Secure Bluetooth-Enabled Cryptographic Provider

The use of digital X509v3 public key certificates, together with different standards for secure digital signatures are commonly adopted to establish authentication proofs between principals, applications and services. One of the robustness characteristics commonly associated with such mechanisms is the need of hardware-sealed cryptographic devices, such as Hardware-Security Modules (or HSMs), smart cards or hardware-enabled tokens or dongles. These devices support internal functions for management and storage of cryptographic keys, allowing the isolated execution of cryptographic operations, with the keys or related sensitive parameters never exposed. The portable devices most widely used are USB-tokens (or security dongles) and internal ships of smart cards (as it is also the case of citizen cards, banking cards or ticketing cards). More recently, a new generation of Bluetooth-enabled smart USB dongles appeared, also suitable to protect cryptographic operations and digital signatures for secure identity and payment applications. The common characteristic of such devices is to offer the required support to be used as secure cryptographic providers. Among the advantages of those portable cryptographic devices is also their portability and ubiquitous use, but, in consequence, they are also frequently forgotten or even lost. USB-enabled devices imply the need of readers, not always and not commonly available for generic smartphones or users working with computing devices. Also, wireless-devices can be specialized or require a development effort to be used as standard cryptographic providers. An alternative to mitigate such problems is the possible adoption of conventional Bluetooth-enabled smartphones, as ubiquitous cryptographic providers to be used, remotely, by client-side applications running in users’ devices, such as desktop or laptop computers. However, the use of smartphones for safe storage and management of private keys and sensitive parameters requires a careful analysis on the adversary model assumptions. The design options to implement a practical and secure smartphone-enabled cryptographic solution as a product, also requires the approach and the better use of the more interesting facilities provided by frameworks, programming environments and mobile operating systems services. In this dissertation we addressed the design, development and experimental evaluation of a secure mobile cryptographic provider, designed as a mobile service provided in a smartphone. The proposed solution is designed for Android-Based smartphones and supports on-demand Bluetooth-enabled cryptographic operations, including standard digital signatures. The addressed mobile cryptographic provider can be used by applications running on Windows-enabled computing devices, requesting digital signatures. The solution relies on the secure storage of private keys related to X509v3 public certificates and Android-based secure elements (SEs). With the materialized solution, an application running in a Windows computing device can request standard digital signatures of documents, transparently executed remotely by the smartphone regarded as a standard cryptographic provider

Quarantine-mode based live patching for zero downtime safety-critical systems

150 p.En esta tesis se presenta una arquitectura y diseño de software, llamado Cetratus, que permite las actualizaciones en caliente en sistemas críticos, donde se efectúan actualizaciones dinámicas de los componentes de la aplicación. La característica principal es la ejecución y monitorización en modo cuarentena, donde la nueva versión del software es ejecutada y monitorizada hasta que se compruebe la confiabilidad de esta nueva versión. Esta característica también ofrece protección contra posibles fallos de software y actualización, así como la propagación de esos fallos a través del sistema. Para este propósito, se emplean técnicas de particionamiento. Aunque la actualización del software es iniciada por el usuario Updater, se necesita la ratificación del auditor para poder proceder y realizar la actualización dinámica. Estos usuarios son autenticados y registrados antes de continuar con la actualización. También se verifica la autenticidad e integridad del parche dinámico. Cetratus está alineado con las normativas de seguridad funcional y de ciber-seguridad industriales respecto a las actualizaciones de software.Se proporcionan dos casos de estudio. Por una parte, en el caso de uso de energía inteligente, se analiza una aplicación de gestión de energía eléctrica, compuesta por un sistema de gestión de energía (BEMS por sus siglas en ingles) y un servicio de optimización de energía en la nube (BEOS por sus siglas en ingles). El BEMS monitoriza y controla las instalaciones de energía eléctrica en un edificio residencial. Toda la información relacionada con la generación, consumo y ahorro es enviada al BEOS, que estima y optimiza el consumo general del edificio para reducir los costes y aumentar la eficiencia energética. En este caso de estudio se incorpora una nueva capa de ciberseguridad para aumentar la ciber-seguridad y privacidad de los datos de los clientes. Específicamente, se utiliza la criptografía homomorfica. Después de la actualización, todos los datos son enviados encriptados al BEOS.Por otro lado, se presenta un caso de estudio ferroviario. En este ejemplo se actualiza el componente Euroradio, que es la que habilita las comunicaciones entre el tren y el equipamiento instalado en las vías en el sistema de gestión de tráfico ferroviario en Europa (ERTMS por sus siglas en ingles). En el ejemplo se actualiza el algoritmo utilizado para el código de autenticación del mensaje (MAC por sus siglas en inglés) basado en el algoritmo de encriptación AES, debido a los fallos de seguridad del algoritmo actual

Extensible metadata repository for information systems

Thesis submitted to Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa, in partial fulfillment of the requirements for the degree of Master in Computer ScienceInformation Systems are, usually, systems that have a strong integration component and some of those systems rely on integration solutions that are based on metadata (data that describes data). In that situation, there’s a need to deal with metadata as if it were “normal”information. For that matter, the existence of a metadata repository that deals with the integrity, storage, validity and eases the processes of information integration in the information system is a wise choice. There are several metadata repositories available in the market, but none of them is prepared to deal with the needs of information systems or is generic enough to deal with the multitude of situations/domains of information and with the necessary integration features. In the SESS project (an European Space Agency project), a generic metadata repository was developed, based on XML technologies. This repository provided the tools for information integration, validity, storage, share, import, as well as system and data integration, but it required the use of fix syntactic rules that were stored in the content of the XML files. This situation causes severe problems when trying to import documents from external data sources (sources unaware of these syntactic rules). In this thesis a metadata repository that provided the same mechanisms of storage, integrity, validity, etc, but is specially focused on easy integration of metadata from any type of external source (in XML format) and provides an environment that simplifies the reuse of already existing types of metadata to build new types of metadata, all this without having to modify the documents it stores was developed. The repository stores XML documents (known as Instances), which are instances of a Concept, that Concept defines a XML structure that validates its Instances. To deal with reuse, a special unit named Fragment, which allows defining a XML structure (which can be created by composing other Fragments) that can be reused by Concepts when defining their own structure. Elements of the repository (Instances,Concepts and Fragment) have an identifier based on (and compatible with) URIs, named Metadata Repository Identifier (MRI). Those identifiers, as well as management information(including relations) are managed by the repository, without the need to use fix syntactic rules, easing integration. A set of tests using documents from the SESS project and from software-house ITDS was used to successfully validate the repository against the thesis objectives of easy integration and promotion of reuse

Decision Support System in National Power Companies. A Practical Example (Part I)

The paper presents the developing stages of the decision support prototype in which the data warehouse and the presentation level are built and validated. The paper also extends the results published in the 12th international conference on Informatics in Economy (IE 2013) proceedings and will presents the major steps for developing the data warehouse that integrates the sources from the Wind Power Plants (WPP) from the national parks and also the interface modules that allow managers to analyze data at a central level

Creating architecture for a digital information system leveraging virtual environments

Abstract. The topic of the thesis was the creation of a proof of concept digital information system, which utilizes virtual environments. The focus was finding a working design, which can then be expanded upon. The research was conducted using design science research, by creating the information system as the artifact. The research was conducted for Nokia Networks in Oulu, Finland; in this document referred to as “the target organization”. An information system is a collection of distributed computing components, which come together to create value for an organization. Information system architecture is generally derived from enterprise architecture, and consists of a data-, technical- and application architectures. Data architecture outlines the data that the system uses, and the policies related to its usage, manipulation and storage. Technical architecture relates to various technological areas, such as networking and protocols, as well as any environmental factors. The application architecture consists of deconstructing the applications that are used in the operations of the information system. Virtual reality is an experience, where the concepts of presence, autonomy and interaction come together to create an immersive alternative to a regular display-based computer environment. The most typical form of virtual reality consists of a headmounted device, controllers and movement-tracking base stations. The user’s head- and body movement can be tracked, which changes their position in the virtual environment. The proof-of-concept information system architecture used a multi-server -based solution, where one central physical server hosted multiple virtual servers. The system consisted of a website, which was the knowledge-center and where a client software could be downloaded. The client software was the authorization portal, which determined the virtual environments that were available to the user. The virtual reality application included functionalities, which enable co-operative, virtualized use of various Nokia products, in immersive environments. The system was tested in working situations, such as during exhibitions with customers. The proof-of-concept system fulfilled many of the functional requirements set for it, allowing for co-operation in the virtual reality. Additionally, a rudimentary model for access control was available in the designed system. The shortcomings of the system were related to areas such as security and scaling, which can be further developed by introducing a cloud-hosted environment to the architecture