59 research outputs found
A theory and model for the evolution of software services
Software services are subject to constant change and variation. To control service development, a service developer needs to know why a change was made, what are its implications and whether the change is complete. Typically, service clients do not perceive the upgraded service immediately. As a consequence, service-based applications may fail on the service client side due to changes carried out during a provider service upgrade. In order to manage changes in a meaningful and effective manner service clients must therefore be considered when service changes are introduced at the service provider's side. Otherwise such changes will most certainly result in severe application disruption. Eliminating spurious results and inconsistencies that may occur due to uncontrolled changes is therefore a necessary condition for the ability of services to evolve gracefully, ensure service stability, and handle variability in their behavior. Towards this goal, this work presents a model and a theoretical framework for the compatible evolution of services based on well-founded theories and techniques from a number of disparate fields.
Security in a Distributed Processing Environment
Distribution plays a key role in telecommunication and computing systems today. It
has become a necessity as a result of deregulation and anti-trust legislation, which has
forced businesses to move from centralised, monolithic systems to distributed systems
with the separation of applications and provisioning technologies, such as the service
and transportation layers in the Internet. The need for reliability and recovery requires
systems to use replication and secondary backup systems such as those used in ecommerce.
There are consequences to distribution. It results in systems being implemented in
heterogeneous environment; it requires systems to be scalable; it results in some loss
of control and so this contributes to the increased security issues that result from
distribution. Each of these issues has to be dealt with. A distributed processing
environment (DPE) is middleware that allows heterogeneous environments to operate
in a homogeneous manner. Scalability can be addressed by using object-oriented
technology to distribute functionality. Security is more difficult to address because it
requires the creation of a distributed trusted environment.
The problem with security in a DPE currently is that it is treated as an adjunct service,
i.e. and after-thought that is the last thing added to the system. As a result, it is not
pervasive and therefore is unable to fully support the other DPE services. DPE
security needs to provide the five basic security services, authentication, access
control, integrity, confidentiality and non-repudiation, in a distributed environment,
while ensuring simple and usable administration.
The research, detailed in this thesis, starts by highlighting the inadequacies of the
existing DPE and its services. It argues that a new management structure was
introduced that provides greater flexibility and configurability, while promoting
mechanism and service independence. A new secure interoperability framework was
introduced which provides the ability to negotiate common mechanism and service
level configurations. New facilities were added to the non-repudiation and audit
services.
The research has shown that all services should be security-aware, and therefore
would able to interact with the Enhanced Security Service in order to provide a more
secure environment within a DPE. As a proof of concept, the Trader service was
selected. Its security limitations were examined, new security behaviour policies
proposed and it was then implemented as a Security-aware Trader, which could
counteract the existing security limitations.IONA TECHNOLOGIES PLC & ORANG
Trust in neoliberal times: A genealogy
There is a crisis of trust in the neoliberal world. Is trust ending, or have we learned to trust in new ways? This thesis conducts an historical genealogy of trust practices across the early modern era, classical liberalism, the welfare state, and neoliberalism. This genealogy reveals that neoliberal trust practices are neither natural nor determined, and that we can inform how we trust in light of our past. This investigation finds that the neoliberal self has little capacity for trust beyond the present moment. Neoliberal trust practices, including auditing, skill learning, risk management, and emotional reasoning, are placed on the market, an unpredictable and erratic force that compels individuals to seek stability and security in isolation from others rather than with others. These attempts to gain security, however, tend to slide towards suspicion, distrust, and alienation. Three ethical implications are discussed regarding the impact of neoliberal trust practices on the therapeutic relationship
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