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.
3571148
Requirement Engineering Meets Security: A Case Study on Modelling Secure Electronic Transactions by VISA and Mastercard
Computer Security is one of today’s hot topic and the need for conceptual models of security features have brought up a number of proposals ranging from UML extensions to novel conceptual models. What is still missing, however, are models that focus on high-level security requirements, without forcing the modeler to immediately get down to security mechanisms. The modeling process itself should make it clear why encryption, authentication or access control are necessary, and what are the tradeoffs, if they are selected. In this paper we show that the i*/Tropos framework lacks the ability to capture these essential features and needs to be augmented. To motivate our proposal, we build upon a substantial case study – the modeling of the Secure Electronic Transactions e-commerce suites by VISA and MasterCard – to identify missing modeling features. In a nutshell, the key missing concept is the separation of the notion of offering a service (of a handling data, performing a task or fulfilling a goal) and ownership of the very same service. This separation is what makes security essential. The ability of the methodology to model a clear dependency relation between those offering a service (the merchant processing a credit card number), those requesting the service (the bank debiting the payment), and those owning the very same data (the cardholder), make security solutions emerge as a natural consequence of the modeling process.
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.
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.
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.
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.
14679432
On Goal-based Variability Acquisition and Analysis
We introduce a variability-intensive approach to goal decomposition that is tailored to support requirements identification for highly customizable software. The approach is based on the semantic characterization of OR-decompositions of goals. We first show that each high-level goal can be associated with a set of concerns, in response to which, alternative refinements of the goal can be introduced. A text corpus relevant to the domain of discourse can be used to derive such variability concerns that are specific to the problem. In parallel, contextual facts that can vary while a goal is being fulfilled are modeled. Then, a high-variability goal model is constructed aiming at responding to the predefined variability concerns completely, while contextual factors are used to test whether it addresses all realistic background circumstances. We apply our approach in a study from the geriatric health care domain
9641490
Discovering the Semantics of Relational Tables Through Mappings
Many problems in Information and Data Management require a semantic account of a database schema. At its best, such an account consists of formulas expressing the relationship (mapping) between the schema and a formal conceptual model or ontology (CM) of the domain. In this paper we describe the underlying principles, algorithms, and a prototype tool that finds such semantic mappings from relational tables to ontologies, when given as input simple correspondences from columns of the tables to datatype properties of classes in an ontology. Although the algorithm presented is necessarily heuristic, we offer formal results showing that the answers returned by the tool are correct for relational schemas designed according to standard Entity-Relationship techniques. To evaluate its usefulness and effectiveness, we have applied the tool to a number of public domain schemas and ontologies. Our experience shows that significant effort is saved when using it to build semantic mappings from relational tables to ontologies.
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.