CA-ABAC: Class Algebra Attribute-Based Access Control

Traditional access control mechanisms prevent illegal access by controlling access right before executing an action; they belong to a class of a priori security solutions and, from this point of view, they have some limitations, like inflexibility in unanticipated circumstances. By contrast, a posteriori mechanisms enforce policies not by preventing unauthorized access, but rather by deterring it. Such access control needs evidence to prove violations. Evidence is derived from one or several log records, which trace each user's actions. Efficiency of violation detection mostly depends on the compliance of log records with the access control policy. In order to develop an efficient method for finding these violations, we propose restructuring log records according to a security policy model. We illustrate our methodology by applying it to the healthcare domain, taking care of the IHE (Integrating the healthcare enterprise) framework, particularly its basic security profile, ATNA (Audit Trail and Node Authentication). This profile defines log records established on the analysis of common health practice scenarios. We analyze and establish how ATNA log records can be refined in order to be integrated into an a posteriori access and usage control process, based on an expressive and contextual security policy like the OrBAC policy.

In recent years we have seen significant advances in the technology used to both publish and consume structured data using the existing web infrastructure, commonly referred to as the Linked Data Web. However, in order to support the next generation of e-business applications on top of Linked Data suitable forms of access control need to be put in place. This paper provides an overview of the various access control models, standards and policy languages, and the different access control enforcement strategies for the Resource Description Framework (the data model underpinning the Linked Data Web). A set of access control requirements that can be used to categorise existing access control strategies is proposed and a number of challenges that still need to be overcome are identified.

The Pi-calculus has been developed to reason about behavioural equivalence. Different notions of equivalence are defined in terms of process interactions, as well as the context of processes. There are various extensions of the Pi-calculus, such as the SPI calculus, which has primitives to facilitate security protocol design.<br /> <br />Another area of computer security is access control research, which includes problems of access control models, policies and access control mechanism. The design of a unified framework for access control requires that all policies are supported and different access control models are instantiated correctly.<br /> <br />In this paper we will utilise the Pi calculus to reason about access control policies and mechanism. An equivalence of different policy implementations, as well as access control mechanism will be shown. Finally some experiences regarding the use of Pi-calculus are presented.

Access control (AC) is a computer security requirement used to control, in a computing environment, what the user can access, when and how. Policy administration is an essential feature of an AC system. As the number of computers are in hundreds of millions, and due to the different organization requirements, applications and needs, various AC models are presented in literature, such as: Discretionary Access Control (DAC), Mandatory Access Control (MAC), Role Based Access Control (RBAC), etc. These models are used to implement organizational policies that prevent the unauthorized disclosure of sensitive data, protecting the data integrity, and enabling secure access and sharing of information. Each AC model has its own methods for making AC decisions and policy enforcement. However, due to the diversity of AC models and the various concerns and restrictions, its essential to find AC metamodels with higher level of abstraction. Access control metamodels serve as a unifying framework for specifying any AC policy and should ease the migration from an AC model to another. This study reviews existing works on metamodels descriptions and representations. But, are the presented metamodels sufficient to handle the needed target of controlling access especially in the presence of the current information technologies? Do they encompass all features of other AC models? In this paper we are presenting a survey on AC metamodels.

Cloud computing paradigm is still an evolving paradigm but has recently gained tremendous momentum due to its potential for significant cost reduction and increased operating efficiencies in computing. However, its unique aspects exacerbate security and privacy challenges that pose as the key roadblock to its fast adoption. Cloud computing has already become very popular, and practitioners need to provide security mechanisms to ensure its secure adoption. In this chapter, the authors discuss access control systems and policy management in cloud computing environments. The cloud computing environments may not allow use of a single access control system, single policy language, or single management tool for the various cloud services that it offers. Currently, users must use diverse access control solutions available for each cloud service provider to secure data. Access control policies may be composed in incompatible ways because of diverse policy languages that are maintained separately at every cloud provider. Heterogeneity and distribution of these policies pose problems in managing access policy rules for a cloud environment. In this chapter, the authors discuss challenges of policy management and introduce a cloud based policy management framework that is designed to give users a unified control point for managing access policies to control access to their resources no matter where they are stored.

PurposeThis paper aims to manage access control tasks to satisfy the user privacy needs of online information resources according to social relations and tags.Design/methodology/approachThe study proposes a method for access control management in the online social context. The proposed method includes the access control policy management process, metadata of access control policies, the data of ontologies, tags, and social relations, and conflict detection rules.FindingsOnline information sharing and hiding, which needs to consider social relations and mentioned topics, is a unique context and needs a novel access control mechanism. Ontologies are powerful and expressive enough to identify conflicts in access control policies. The paper provides a method using ontologies to control the access control activities based on social relations and tags on web content. The effectiveness of the method's conflict detection rules is validated through several scenarios.Research limitations/implicationsTo make the proposed method suitable for widespread usage, further work is required to develop an access control policy specification and conflict detection tool. The proposed method introduces relatively novel usage scenarios, which consider social relationships, and tags compared with existing access control methods for online information sharing.Practical implicationsThe proposed access control mechanism can be integrated into existing web sites. Online users can use this method to share information more easily than at present.Originality/valueThe method enables flexible access control in social contexts and handles unavoidable conflicts. It also opens the way to new access control scenarios in online social activities. The method can be used to keep secrets hidden from selected people.

Traditionally, access control is enforced by centralized stand-alone architectures. In this case, the access controller “knows” all information necessary to evaluate the access control policy. As a consequence, when a subject sends a query to the access controller, this access controller does not need to interact with this subject to decide if this query must be accepted or rejected. However, in more recent architectures, such a centralized evaluation of the access control policy is no longer appropriate. When a subject sends a query to the access controller, this controller needs to interact with the subject through a negotiation protocol. The objective of this protocol is to exchange additional information necessary to evaluate the policy. This information generally correspond to credentials the subject has to provide to prove that he or she satisfies the requirements to execute the query. Notice that the negotiation protocol can actually behave in a symmetric way in the sense that the access controller may also exchange credentials to provide the subject with guarantees that this subject can interact securely with the controller. The objective of the negotiation is to exchange credentials in order to decide if the query must be accepted or not. When the access control policy corresponds to a set of permission rules, this consists in determining if the query matches one of these permission rules. However, the access control policy may also include prohibitions that act as exception to the permissions. In that case, the negotiation protocol must decide if (1) there is a permission to accept the query and (2) there is no prohibition that would apply to deny the query.

Network Functions Virtualization (NFV) has been widely recognized as an effective way to implement and consolidate hardware-based network functions by using software-based approaches, with a potential to significantly reducing CAPEX and OPEX. In particular, NFV orchestrators (e.g., Tacker, Cloudify, and ONAP) play a vital role in managing and orchestrating various virtualized network resources (e.g., VMs, Virtualized Network Functions), and TOSCA is one of the standard data models to fulfil such a role. However, it remains unclear how the security mechanisms can be seamlessly integrated into the entire lifecycle of those virtualized network assets. Starting with a comparative analysis on the available NFV orchestrators, we extend the TOSCA model to incorporate security attributes of interest, and leverage the extended model to create access control policies at cloud scale. Specifically, a security orchestrator is developed, which contains a TOSCA-parser and a novel tenant-specific access control paradigm. One of the salient features of our security orchestrator is that it allows to dynamically generate access control models and policies for different tenant domains, resulting in a flexible and scalable protection coverage that is across different NFV layers and multiple data centers. To validate its feasibility and effectiveness, we develop a security orchestrator prototype and test its performance with respect to throughput, scalability, and adaptability. The experimental results demonstrate that all the desirable properties can be achieved, and the throughput of our security orchestrator can be maintained at a satisfactory level regardless of the varying number of tenants, users, or objects that are deployed in the cloud.

XACML is a powerful and flexible access control (AC) policy language. It is an OASIS standard that is now widely used in a variety of applications, particularly those that require inter-operability between AC systems. The language definition includes a precise grammar, syntax, and semantics, and it is both expressive and verbose. This combination of expressive power and verbosity can lead to difficulty in understanding the language's syntax and semantics for both technical and nontechnical users alike. As a result, reducing the difficulty of editing XACML policies has become an intense area of research. In our own work in this area, we previously showed how to render complex XACML conditions using a non-technical display notation and showed that it is easy to use this notation with interactive plain text editors that do not require any technical coding. Although XACML conditions are expressive and flexible, XACML targets are actually the most commonly used XACML language construct. They have an additional level of complexity, especially in version 3.0, due to the fact that the form and kinds of XACML constructs allowed in targets is much more limited. This paper extends our previous work, showing how the same powerful and flexible interactive editing principles can be applied to targets in order to allow users to use natural logic rather than implementation logic. We extend these principles and fully integrate them into our editing tool, easy XACML. This tool is usable by users with no technical knowledge of XACML, thus making XACML totally transparent to the user, while still retaining all of its functionalities and semantics. Our tool thus allows users to focus on policy logic rather than on details of syntax. As a result, the risk of errors in policies is greatly reduced.

We propose formal analysis of access control policies associated with business processes. Formal analysis of such policies enables us to investigate certain properties of interest and determine whether they hold. Discovering whether these policies create the intended effects, especially when the number of policies is increased and often composed, can become complex. In addition, we believe that access control policies must be specified in such a way that their integration into business processes is straightforward. Prior research has focused on formal verification of either access control policies or business processes but not viewed the two as an integrated whole. We show an approach in which access control policies and business processes are described using the same foundational building blocks, consequently, integration of access control policies and business processes is significantly less complex. Furthermore, access control policies can now be described by business patterns, and this description may result in discovery of access control patterns that can be used in the future. Finally, our approach through the use of business patterns is capable of modeling access control policies in the same way an access control model does. In addition, these policies can be specified and extended using rules, and in this respect, are akin to a policy language.

Traditional access control models often assume that the entity enforcing access control policies is also the owner of data and resources. This assumption no longer holds when data is outsourced to a third-party storage provider, such as the cloud. Existing access control solutions mainly focus on preserving confidentiality of stored data from unauthorized access and the storage provider. However, in this setting, access control policies as well as users’ access patterns also become privacy sensitive information that should be protected from the cloud. We propose a two-level access control scheme that combines coarse-grained access control enforced at the cloud, which provides acceptable communication overhead and at the same time limits the information that the cloud learns from his partial view of the access rules and the access patterns, and fine-grained cryptographic access control enforced at the user’s side, which provides the desired expressiveness of the access control policies. Our solution handles both read and write access control.KeywordsAccess ControlAccess PatternCloud ProviderData OwnerAccess Control PolicyThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Multimedia data and information systems manage, communicate, and present multimedia data including text, images, audio and video. We need to ensure that the data is protected from unauthorized access as well as malicious corruption. Digital watermarking techniques that insert hidden copyright messages into the multimedia data are needed. Furthermore, since multimedia data is being used for security applications such as surveillance and monitoring, protecting privacy of the individual is crucial.This presentation will discuss the developments and directions for securing multimedia systems. First we will first issues on incorporating security into multimedia data and information systems. We will review various security mechanisms and access control policies and discuss the applicability of these mechanisms and policies for multimedia data. Second, we will examine the developments of digital libraries, which can be considered to be special kinds of multimedia data and information systems, and discuss various developments on secure digital libraries. Access control models such as role-based access control and copyright protection methods for digital libraries will be discussed. Third, we will discuss the developments in securing multimedia communication systems including VoIP security. Emerging novel techniques in digital watermarking as well as the use of multimedia data for computer forensics analysis will also be discussed. Finally, the applications of multimedia data for surveillance and monitoring as well as video data analysis for national security applications will be discussed. Privacy violations that could occur through multimedia data mining as well as directions for privacy preserving surveillance and privacy preserving multimedia data mining will be discussed.

Healthcare information systems deal with sensitive data across complex workflows. They often allow various stakeholders from different environments to access data across organizational boundaries. This elevates the risk of exposing sensitive healthcare information to unauthorized personnel, leading ‘controlling access to resources' a major concern. To prevent unwanted access to sensitive information, healthcare organizations need to adopt effective workflows and access control mechanisms. Many healthcare organizations are not yet considering or do not know how to accommodate the ‘context' element as a crucial element in their workflows and access control policies. The authors envision the future of healthcare where ‘context' will be considered as a crucial element. They can accommodate context through a new element ‘environment' in workflows, and can accommodate context in policies through well-known attribute based access control mechanism (ABAC). This research mainly addresses these problems by proposing a model to integrate workflows and access control policies and thereby identifying workflow activities that are not being protected by access control policies and improving the workflow activities and/or existing access control policies using SARE (Subject, Action, Resource, and environment) elements.

Healthcare information systems deal with sensitive data across complex workflows. They often allow various stakeholders from different environments to access data across organizational boundaries. This elevates the risk of exposing sensitive healthcare information to unauthorized personnel, leading ‘controlling access to resources' a major concern. To prevent unwanted access to sensitive information, healthcare organizations need to adopt effective workflows and access control mechanisms. Many healthcare organizations are not yet considering or do not know how to accommodate the ‘context' element as a crucial element in their workflows and access control policies. The authors envision the future of healthcare where ‘context' will be considered as a crucial element. They can accommodate context through a new element ‘environment' in workflows, and can accommodate context in policies through well-known attribute based access control mechanism (ABAC). This research mainly addresses these problems by proposing a model to integrate workflows and access control policies and thereby identifying workflow activities that are not being protected by access control policies and improving the workflow activities and/or existing access control policies using SARE (Subject, Action, Resource, and environment) elements.

Access control is the process of mediating every request to resources and data maintained by a system and determining whether the request should be granted or denied. The access control decision is enforced by a mechanism implementing regulations established by a security policy. Different access control policies can be applied, corresponding to different criteria for defining what should, and what should not, be allowed, and, in some sense, to different definitions of what ensuring security means. In this chapter we investigate the basic concepts behind access control design and enforcement, and point out different security requirements that may need to be taken into consideration. We discuss several access control policies, and models formalizing them, that have been proposed in the literature or that are currently under investigation.