On Properties of Policy-Based Specifications

The advent of large-scale, complex computing systems has dramatically increased the difficulties of securing accesses to systems' resources. To ensure confidentiality and integrity, the exploitation of access control mechanisms has thus become a crucial issue in the design of modern computing systems. Among the different access control approaches proposed in the last decades, the policy-based one permits to capture, by resorting to the concept of attribute, all systems' security-relevant information and to be, at the same time, sufficiently flexible and expressive to represent the other approaches. In this paper, we move a step further to understand the effectiveness of policy-based specifications by studying how they permit to enforce traditional security properties. To support system designers in developing and maintaining policy-based specifications, we formalise also some relevant properties regarding the structure of policies. By means of a case study from the banking domain, we present real instances of such properties and outline an approach towards their automatised verification.Comment: In Proceedings WWV 2015, arXiv:1508.0338

Common Representation of Information Flows for Dynamic Coalitions

We propose a formal foundation for reasoning about access control policies within a Dynamic Coalition, defining an abstraction over existing access control models and providing mechanisms for translation of those models into information-flow domain. The abstracted information-flow domain model, called a Common Representation, can then be used for defining a way to control the evolution of Dynamic Coalitions with respect to information flow

From Conventional to State-of-the-Art IoT Access Control Models

open access articleThe advent in Online Social Networks (OSN) and Internet of Things (IoT) has created a new world of collaboration and communication between people and devices. The domain of internet of things uses billions of devices (ranging from tiny sensors to macro scale devices) that continuously produce and exchange huge amounts of data with people and applications. Similarly, more than a billion people are connected through social networking sites to collaborate and share their knowledge. The applications of IoT such as smart health, smart city, social networking, video surveillance and vehicular communication are quickly evolving people’s daily lives. These applications provide accurate, information-rich and personalized services to the users. However, providing personalized information comes at the cost of accessing private information of users such as their location, social relationship details, health information and daily activities. When the information is accessible online, there is always a chance that it can be used maliciously by unauthorized entities. Therefore, an effective access control mechanism must be employed to ensure the security and privacy of entities using OSN and IoT services. Access control refers to a process which can restrict user’s access to data and resources. It enforces access rules to grant authorized users an access to resources and prevent others. This survey examines the increasing literature on access control for traditional models in general, and for OSN and IoT in specific. Challenges and problems related to access control mechanisms are explored to facilitate the adoption of access control solutions in OSN and IoT scenarios. The survey provides a review of the requirements for access control enforcement, discusses several security issues in access control, and elaborates underlying principles and limitations of famous access control models. We evaluate the feasibility of current access control models for OSN and IoT and provide the future development direction of access control for the sam

A Design of MAC Model Based on the Separation of Duties and Data Coloring: DSDC-MAC

Among the access control methods for database security, there is Mandatory Access Control (MAC) model in which the security level is set to both the subject and the object to enhance the security control. Legacy MAC models have focused only on one thing, either confidentiality or integrity. Thus, it can cause collisions between security policies in supporting confidentiality and integrity simultaneously. In addition, they do not provide a granular security class policy of subjects and objects in terms of subjects\u27 roles or tasks. In this paper, we present the security policy of Bell_LaPadula Model (BLP) model and Biba model as one complemented policy. In addition, Duties Separation and Data Coloring (DSDC)-MAC model applying new data coloring security method is proposed to enable granular access control from the viewpoint of Segregation of Duty (SoD). The case study demonstrated that the proposed modeling work maintains the practicality through the design of Human Resources management System. The proposed model in this study is suitable for organizations like military forces or intelligence agencies where confidential information should be carefully handled. Furthermore, this model is expected to protect systems against malicious insiders and improve the confidentiality and integrity of data

Aspect-based approach to modeling access control policies, An

Department Head: L. Darrell Whitley.2007 Spring.Includes bibliographical references (pages 119-126).Access control policies determine how sensitive information and computing resources are to be protected. Enforcing these policies in a system design typically results in access control features that crosscut the dominant structure of the design (that is, features that are spread across and intertwined with other features in the design). The spreading and intertwining of access control features make it difficult to understand, analyze, and change them and thus complicate the task of ensuring that an evolving design continues to enforce access control policies. Researchers have advocated the use of aspect-oriented modeling (AOM) techniques for addressing the problem of evolving crosscutting features. This dissertation proposes an approach to modeling and analyzing crosscutting access control features. The approach utilizes AOM techniques to isolate crosscutting access control features as patterns described by aspect models. Incorporating an access control feature into a design involves embedding instantiated forms of the access control pattern into the design model. When composing instantiated access control patterns with a design model, one needs to ensure that the resulting composed model enforces access control policies. The approach includes a technique to verify that specified policies are enforced in the composed model. The approach is illustrated using two well-known access control models: the Role- Based Access Control (RBAC) model and the Bell-LaPadula (BLP) model. Features that enforce RBAC and BLP models are described by aspect models. We show how the aspect models can be composed to create a new hybrid access control aspect model. We also show how one can verify that composition of a base (primary) design model and an aspect model that enforces specified policies produces a composed model in which the policies are still enforced

Analyzing and developing role-based access control models

Role-based access control (RBAC) has become today's dominant access control model, and many of its theoretical and practical aspects are well understood. However, certain aspects of more advanced RBAC models, such as the relationship between permission usage and role activation and the interaction between inheritance and constraints, remain poorly understood. Moreover, the computational complexity of some important problems in RBAC remains unknown. In this thesis we consider these issues, develop new RBAC models and answer a number of these questions. We develop an extended RBAC model that proposes an alternative way to distinguish between activation and usage hierarchies. Our extended RBAC model has well-defined semantics, derived from a graph-based interpretation of RBAC state. Pervasive computing environments have created a requirement for access control systems in which authorization is dependent on spatio-temporal constraints. We develop a family of simple, expressive and flexible spatio-temporal RBAC models, and extend these models to include activation and usage hierarchies. Unlike existing work, our models address the interaction between spatio-temporal constraints and inheritance in RBAC, and are consistent and compatible with the ANSI RBAC standard. A number of interesting problems have been defined and studied in the context of RBAC recently. We explore some variations on the set cover problem and use these variations to establish the computational complexity of these problems. Most importantly, we prove that the minimal cover problem -- a generalization of the set cover problem -- is NP-hard. The minimal cover problem is then used to determine the complexity of the inter-domain role mapping problem and the user authorization query problem in RBAC. We also design a number of efficient heuristic algorithms to answer the minimal cover problem, and conduct experiments to evaluate the quality of these algorithms.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Possibilistic Information Flow Control for Workflow Management Systems

In workflows and business processes, there are often security requirements on both the data, i.e. confidentiality and integrity, and the process, e.g. separation of duty. Graphical notations exist for specifying both workflows and associated security requirements. We present an approach for formally verifying that a workflow satisfies such security requirements. For this purpose, we define the semantics of a workflow as a state-event system and formalise security properties in a trace-based way, i.e. on an abstract level without depending on details of enforcement mechanisms such as Role-Based Access Control (RBAC). This formal model then allows us to build upon well-known verification techniques for information flow control. We describe how a compositional verification methodology for possibilistic information flow can be adapted to verify that a specification of a distributed workflow management system satisfies security requirements on both data and processes.Comment: In Proceedings GraMSec 2014, arXiv:1404.163