Shinren : Non-monotonic trust management for distributed systems

The open and dynamic nature of modern distributed systems and pervasive environments presents significant challenges to security management. One solution may be trust management which utilises the notion of trust in order to specify and interpret security policies and make decisions on security-related actions. Most trust management systems assume monotonicity where additional information can only result in the increasing of trust. The monotonic assumption oversimplifies the real world by not considering negative information, thus it cannot handle many real world scenarios. In this paper we present Shinren, a novel non-monotonic trust management system based on bilattice theory and the anyworld assumption. Shinren takes into account negative information and supports reasoning with incomplete information, uncertainty and inconsistency. Information from multiple sources such as credentials, recommendations, reputation and local knowledge can be used and combined in order to establish trust. Shinren also supports prioritisation which is important in decision making and resolving modality conflicts that are caused by non-monotonicity

Information sharing, liquidity and transaction costs in floor-based trading systems

We consider information sharing between traders("floor brokers") who possess different types of information, namely information on the payoff of a risky security or information on the volume of liquidity trading in this security. We interpret these traders as dual -capacity brokers on the floor of an exchange. We identify conditions under which the traders are better off sharing information. We also show that information sharing improves price discovery, reduces volatility and lowers expected trading costs. Information sharing can improve or impair the depth of the market, depending on the values of the parameters. Overall our analysis suggests that information sharing among floor brokers improves the performance of floor-based trading systems.market microstructure; floor-based trading systems; open outcry; information sharing; information sales

Основні принципи інформаційної безпеки відкритих систем. Частина 2. Властивості відкритих систем та вимоги до інтелектуального управління

Аналізуються новітні науково-технічні досягнення у області інформатики, інформаційних технологій та виводяться основні принципи інформаційної безпеки відкритих систем, що характеризуються інтелектульним управлінням й активною взаємодією з іншими системами. Виявляються властивості відкритих систем та формульються вимоги до інтелектуального управління з точки зору їх інформаційної безпеки.The newest scientific-technical achievements in informatics, information technologies and main principles of information security open systems, which characterized intellectual control and active interaction with other systems, are analyzed. Properties of open system are defined are formulated for intellectual control of them from the point of view of their information security

ontext-aware security and secure context-awareness in ubiquitous computing environments

Context-awareness emerges as an important element of future wireless systems. In particular, concepts like ambient intelligence and ubiquitous computing rely on context information in order to personalize services provided to their target users. However, security implications of employing context-awareness in computing systems are not well understood. Security challenges in context-aware systems include integrity, confidentiality and availability of context information, as well as target user's privacy. Another interesting and open question is to what extent availability of additional context information could be used in order to optimise and reconfigure security-related services

Security and immutability of open data in healthcare

Clinical data are sensitive data given the origin of the information. Since the implementation of health information systems, some issues such as interoperability, security, and privacy have been strongly questioned. Storing and consulting them raises the same concerns. Given these concerns, any attempt to introduce healthcare information systems must guarantee the security and privacy, integrity, and immutability of patient information. It is in this sense that blockchain technology and the openEHR open data model appear, as they manage to guarantee interoperability between systems, data security and guarantees about queries of each stored data. In order to understand how to increase security and immutability in an implementation of open data models in hospitals, two distinct architectures were developed. In these architectures, several performance tests were carried out. To understand which of them represents more value to a health institution, an analysis of the results was prepared and, consequently, a discussion about them was held to be able to draw the respective conclusions.(undefined