8955752
Modeling Social and Individual Trust in Requirements Engineering Methodologies
When we model and analyze trust in organizations or information systems we have to take into account two different levels of analysis: social and individual. Social levels define the structure of organizations, whereas individual levels focus on individual agents. This is particularly important when capturing security requirements where a “normally” trusted organizational role can be played by an untrusted individual. 
 
Our goal is to model and analyze the two levels finding the link between them and supporting the automatic detection of conflicts that can come up when agents play roles in the organization. We also propose a formal framework that allows for the automatic verification of security requirements between the two levels by using Datalog and has been implemented in CASE tool.
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.
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.
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].
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.
14897100
Model checking early requirements specifications in Tropos
We describe an attempt to bridge the gap between early requirements specification and formal methods. In particular, we propose a new specification language, called Formal Tropos, that is founded on the primitive concepts of early requirements frameworks (actor, goal, strategic dependency) (Yu, 1997), but supplements them with a rich temporal specification language. We also extend existing formal analysis techniques, in particular model checking, to allow for an automatic verification of relevant properties for an early requirements specification. Our preliminary experiments demonstrate that formal analysis reveals gaps and inconsistencies in early requirements that are by no means trivial to discover without the help of formal analysis tools.
18763107
Building Semantic Mappings from Databases to Ontologies
A recent special issue of AI Magazine (AAAI 2005) was dedicated to the topic of semantic integration -- the problem of sharing data across disparate sources. At the core of the solution lies the discovery the "semantics" of different data sources. Ideally, the semantics of data are captured by a formal ontology of the domain together with a semantic mapping connecting the schema describing the data to the ontology. However, establishing the semantic mapping from a database schema to a formal ontology in terms of formal logic expressions is inherently difficult to automate, so the task was left to humans. In this paper, we report on our study (An, Borgida, & Mylopoulos 2005a; 2005b) of a semi-automatic tool, called MAPONTO, that assists users to discover plausible semantic relationships between a database schema (relational or XML) and an ontology, expressing them as logical formulas/rules.
596050
Building knowledge base management systems

Abstract.Advanced applications in fields such as CAD, software engineering, real-time process control, corporate repositories and digital libraries require the construction, efficient access and management of large, shared knowledge bases. Such knowledge bases cannot be built using existing tools such as expert system shells, because these do not scale up, nor can they be built in terms of existing database technology, because such technology does not support the rich representational structure and inference mechanisms required for knowledge-based systems. This paper proposes a generic architecture for a knowledge base management system intended for such applications. The architecture assumes an object-oriented knowledge representation language with an assertional sublanguage used to express constraints and rules. It also provides for general-purpose deductive inference and special-purpose temporal reasoning. Results reported in the paper address several knowledge base management issues. For storage management, a new method is proposed for generating a logical schema for a given knowledge base. Query processing algorithms are offered for semantic and physical query optimization, along with an enhanced cost model for query cost estimation. On concurrency control, the paper describes a novel concurrency control policy which takes advantage of knowledge base structure and is shown to outperform two-phase locking for highly structured knowledge bases and update-intensive transactions. Finally, algorithms for compilation and efficient processing of constraints and rules during knowledge base operations are described. The paper describes original results, including novel data structures and algorithms, as well as preliminary performance evaluation data. Based on these results, we conclude that knowledge base management systems which can accommodate large knowledge bases are feasible.

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.
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.