6310113
Requirements Engineering Meets Trust Management: Model, Methodology, and Reasoning
The last years have seen a number of proposals to incorporate Security Engineering into mainstream Software Requirements Engineering. However, capturing trust and security requirements at an organizational level (as opposed to a design level) is still an open problem. This paper presents a formal framework for modeling and analyzing security and trust requirements. It extends the Tropos methodology, an agent-oriented software engineering methodology. The key intuition is that in modeling security and trust, we need to distinguish between the actors that manipulate resources, accomplish goals or execute tasks, and actors that own the resources or the goals. To analyze an organization and its information systems, we proceed in two steps. First, we built a trust model, determining the trust relationships among actors, and then we give a functional model, where we analyze the actual delegations against the trust model, checking whether an actor that offers a service is authorized to have it. The formal framework allows for the automatic verification of security and trust requirements by using a suitable delegation logic that can be mechanized within Datalog. To make the discussion more concrete, we illustrate the proposal with a Health Care case study.
1423082
Data Management for Peer-to-Peer Computing : A Vision
We motivate special database problems introduced by peer-to-peer computing and propose the Local Relational Model (LRM) to solve some of them. As well, we summarize a formalization of LRM, present an architecture for a prototype implementation, and discuss open research questions.
6657466
Local Relational Model: A Logical Formalization of Database Coordination
We propose a new data model intended for peer-to-peer (P2P) databases. The model assumes that each peer has a (relational) database and exchanges data with other peers (its acquaintances). In this context, one needs a data model that views the space of available data within the P2P network as an open collection of possibly overlapping and inconsistent databases. Accordingly, the paper proposes the Local Relational Model, develops a semantics for coordination formulas. The main result of the paper generalizes Reiter's characterization of a relational database in terms of a first order theory [1], by providing a syntactic characterization of a relational space in terms of a multi-context system. This work extends earlier work by Giunchiglia and Ghidini on Local Model Semantics [2].
3507397
A knowledge level software engineering methodology for agent oriented programming
Our goal in this paper is to introduce and motivate a methodology, called \emph{Tropos}, for building agent oriented software systems. Tropos is based on two key ideas. First, the notion of agent and all the related mentalistic notions (for instance: beliefs, goals, actions and plans) are used in all phases of software development, from the early analysis down to the actual implementation. Second, Tropos covers also the very early phases of requirements analysis, thus allowing for a deeper understanding of the environment where the software must operate, and of the kind of interactions that should occur between software and human agents. The methodology is illustrated with the help of a case study.
38499377
The Tropos Software Development Methodology: Processes, Models and Diagrams
Tropos is a novel agent-oriented software development methodology founded on two key features: (i) the notions of agent, goal, plan and various other knowledge level concepts are fundamental primitives used uniformly throughout the software development process; and (ii) a crucial role is assigned to requirements analysis and specification when the system-to-be is analyzed with respect to its intended environment. This paper describes the basic concepts on which Tropos is founded and the types of models one builds out of them. We also specify the analysis process through which design flows from external to system actors through a goal analysis and delegation. In addition, we provide an abstract syntax for Tropos diagrams and other linguistic constructs.
2515059
Modeling security requirements through ownership, permission and delegation
Security requirements engineering is emerging as a branch of software engineering, spurred by the realization that security must be dealt with early on during the requirements phase. Methodologies in this field are challenging, as they must take into account subtle notions such as trust (or lack thereof), delegation, and permission; they must also model entire organizations and not only systems-to-be. In our previous work we introduced Secure Tropos, a formal framework for modeling and analyzing security requirements. Secure Tropos is founded on three main notions: ownership, trust, and delegation. In this paper, we refine Secure Tropos introducing the notions of at-least delegation and trust of execution; also, at-most delegation and trust of permission. We also propose monitoring as a security design pattern intended to overcome the problem of lack of trust between actors. The paper presents a semantic for these notions, and describes an implemented formal reasoning tool based on Datalog.
464743
Specifying and analyzing early requirements in Tropos
We present a framework that supports the formal verification of early requirements specifications. The framework is based on Formal Tropos, a specification language that adopts primitive concepts for modeling early requirements (such as actor, goal, and strategic dependency), along with a rich temporal specification language. We show how existing formal analysis techniques, and in particular model checking, can be adapted for the automatic verification of Formal Tropos specifications. These techniques have been implemented in a tool, called the T-Tool, that maps Formal Tropos specifications into a language that can be handled by the NuSMV model checker. Finally, we evaluate our methodology on a course-exam management case study. Our experiments show that formal analysis reveals gaps and inconsistencies in early requirements specifications that are by no means trivial to discover without the help of formal analysis tools.
2115447
Security and privacy requirements analysis within a social setting
Security issues for software systems ultimately concern relationships among social actors stakeholders, system users, potential attackers - and the software acting on their behalf. We propose a methodological framework for dealing with security and privacy requirements based on i*, an agent-oriented requirements modeling language. The framework supports a set of analysis techniques. In particular, attacker analysis helps identify potential system abusers and their malicious intents. Dependency vulnerability analysis helps detect vulnerabilities in terms of organizational relationships among stakeholders. Countermeasure analysis supports the dynamic decision-making process of defensive system players in addressing vulnerabilities and threats. Finally, access control analysis bridges the gap between security requirement models and security implementation models. The framework is illustrated with an example involving security and privacy concerns in the design of agent-based health information systems. In addition, we discuss model evaluation techniques, including qualitative goal model analysis and property verification techniques based on model checking.
14238197
Data Semantics Revisited
The problem of data semantics is establishing and maintaining the correspondence between a data source and its intended subject matter. We review the long history of the problem in Databases, and contrast it with recent research on the Semantic Web. We then propose two new directions for research on the problem and sketch some open research questions.
5771700
Information services for the Web: building and maintaining domain models
The World Wide Web is serving as a leading vehicle for information dissemination by offering information services, such as product information, group interactions, or sales transactions. Three major factors affect the performance and reliability of information services for the Web: the distribution of information which has resulted from the globalization of information systems, the heterogeneity of information sources, and the sources' instability caused by their autonomous evolution. This paper focuses on integrating existing information sources, available via the Web, in the delivery of information services. The primary objective of the paper is to provide mechanisms for structuring and maintaining a domain model for Web applications. These mechanisms are based on conceptual modeling techniques, where concepts are being defined and refined within a meta-data repository through the use of instantiation, generalization and attribution. Also, active databases techniques are exploited to provide robust mechanisms for maintaining a consistent domain model in a rapidly evolving environment, such as the Web.
12169882
Capturing more world knowledge in the requirements specification
The view is adopted that software requirements involve the representation (modeling) of considerable real-world knowledge, not just functional specifications. A framework (RMF) for requirements models is presented and its main features are illustrated. RMF allows information about three types of conceptual entities (objects, activities, and assertions) to be recorded uniformly using the notion of properties. By grouping all entities into classes or metaclasses, and by organizing classes into generalization (specialization) hierarchies, RMF supports three abstraction principles (classification, aggregation, and generalization) which appear to be of universal importance in the development and organization of complex descriptions. Finally, by providing a mathematical model underlying our terminology, we achieve both unambiguity and the potential to verify consistency of the model.