Multi-dimensional Forwarding Tables

Role based Access Control (RBAC) is known as an evolution in the field of access control. The strength of RBAC is considered due to the incorporation of concept of roles. Separation of Duty (SOD) is a constraint that implements least privilege principle in RBAC. Dynamic Separation of Duty (DSD) is a powerful constraint to control internal security threats. Current RBAC standard implements DSD on the level of roles. This creates various problems. In this paper, various problems in case of implementing DSD on the level of roles are identified. We show and prove that RBAC's strength is the incorporation of concept of roles but this is not for better security in terms of authorization. Instead this helps in better administration or usability for users. The RBAC usability can be improved if RBAC administration is being implemented on the basis of roles and access control can be more secure if DSD is being implemented on the basis of conflicting permissions. The concept of normalized roles is also introduced. The proposed model implements access control on the basis of normalized role. DSD is being implemented on the basis of conflicting permissions and non-conflicting permissions are exercised under the umbrella of role. This becomes a hybrid approach for access control. The administrators are given freedom in implementing DSD in various modes according to the organizational requirements from lenient to strict implementation. The proposed model is also formally specified and the benefits as a result of implementing the proposed model are discussed.

In many domains, organizations must model personnel and corresponding data access privileges as fine-grained hierarchical access control models. One class of such models, Role-based Access Control (RBAC) models, has been widely accepted and deployed. However, RBAC models are often used without involving cryptographic keys nor considering confidentiality/privacy at the data level. How to design, implement and dynamically modify such a hierarchy, ensure user and data privacy and distribute and manage necessary cryptographic keys are issues of the utmost importance. One elegant solution for cryptography-based hierarchical access control combines the collusion-resistant and privacy-preserving Access Control Polynomial (ACP) and Atallah's Dynamic and Efficient Extended Key Management scheme. Such a model involves cryptographic keys used to encrypt data, can address confidentiality/privacy at the data level and can efficiently support dynamic changes to the RBAC access hierarchy. In this paper, we discuss several implementation challenges and propose solutions when deploying such a system including: data encryption and decryption, key storage and key distribution. Furthermore, we provide analysis of the efficiency and scalability of the resulting system.

Traditional firewalls have the ability to allow or block traffic based on source address as well as destination address and port number. Our original ROFL scheme implements firewalling by layering it on top of routing; however, the original proposal focused just on destination address and port number. Doing route selection based in part on source addresses is a form of policy routing, which has started to receive increased amounts of attention. In this paper, we extend the original ROFL (ROuting as the Firewall Layer) scheme by including source prefix constraints in route announcement. We present algorithms for route propagation and packet forwarding, and demonstrate the correctness of these algorithms using rigorous proofs. The new scheme not only accomplishes the complete set of filtering functionality provided by traditional firewalls, but also introduces a new direction for policy routing.

Recently there has been considerable interest in role-based access control (RBAC) as an alternative, and supplement, to the traditional discretionary and mandatory access controls (DAC and MAC) embodied in the Orange Book. The roots of RBAC can be traced back to the earliest access control systems. Roles have been used in a number of systems for segregating various aspects of security and system administration. Recent interest in RBAC has been motivated by the use of roles at the application level to control access to application data. This is an important innovation which offers the opportunity to realize benefits in securing an organization's information assets, similar to the benefits of employing databases instead of files as the data repository. A number of proposals for RBAC have been published in the literature, but there is no consensus on precisely what is meant by RBAC. This paper lays the groundwork for developing this consensus. In our view RBAC is a concept which has several dimensions, all of which may not be present in a given system or product. We envisage each dimension as being linearly ordered with respect to the sophistication of features provided. This leads us to the idea of a multi-dimension model for RBAC. Achieving agreement on what these dimensions are, and how the features in each dimension should be ordered, will take debate and time. Our contribution here is to lay out a vision on how to approach a common understanding of RBAC, and take a first cut at identifying the dimensions of RBAC. A major benefit of such a multidimensional RBAC would be to allow comparison of different products and assess their appropriateness for various system requirements.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Role-based access control (RBAC) continues to gain popularity in the management of authorization concerning access to knowledge assets in organizations. As a socio-technical concept, the notion of role in RBAC has been overemphasized, while very little attention is given to the precursors: role strain, role ambiguity, and role conflict. These constructs provide more significant insights into RBAC design in Knowledge Management Systems (KMS). KMS is the technology-based knowledge management tool used to acquire, store, share, and apply knowledge for improved collaboration and knowledge-value creation. In this paper, we propose eight propositions that require future research concerning the RBAC system for knowledge security. In addition, we propose a model that integrates these precursors and RBAC to deepen the understanding of these constructs. Further, we examine these precursory constructs in a socio-technical fashion relative to RBAC in the organizational context and the status–role relationship effects. We carried out conceptual analysis and synthesis of the relevant literature, and present a model that involves the three essential precursors that play crucial roles in role mining and engineering in RBAC design. Using an illustrative case study of two companies where 63 IT professionals participated in the study, the study established that the precursors positively and significantly increase the intractability of the RBAC system design. Our framework draws attention to both the management of organizations and RBAC system developers about the need to consider and analyze the precursors thoroughly before initiating the processes of policy engineering, role mining, and role engineering. The propositions stated in this study are important considerations for future work.

The importance of security-enhancing mechanisms at the kernel level, such as an access control, has been increasingly emphasized as the weaknesses and limitation of mechanisms at the user level have been revealed. Among many access controls available, role based access control (RBAC) is mandatory and supports the separation of duty when compared to discretionary access control (DAC). With these advantages, RBAC has been widely implemented at various levels of computing environments, such as the operating system and database management system levels. However, the overheads for supporting all of the RBAC features and flexibility are significant. We designed a fast, simple, and mandatory access control model with some RBAC and DAC characteristics, then implemented a prototype and measured its overheads.

Access control is an important protection mechanism for information system. Access control enforces subjects access restrictions to objects. Legitimate users should be allowed to access objects and illegitimate users should be detained from accessing objects. Access control between multi-user and multi-object is the key technique in security management of workflow management systems (WfMS), and the mechanism of the role-based authorization and access control is an effective way to solve the problem. This paper designs a set of practical constraint mechanism of role-based access control for WfMS. After introducing authorization constraint mechanism, a new model of role-based access control, RBACWF, is proposed. The role assignment algorithm, role-assign(tasknumber, pre_ass) , is also given as a key technique in this model. After this, an application example is given to explain the execution of the algorithm. Finally, a practical WfMS based on above designs is supplied. The practice in the system’s design and execution has proved that the authorization mechanism is flexible, the performance of the access security is improved greatly, and it also simplifies the task complexity of security administrator.

Role-based access control (RBAC) is useful in information security. It is a super set of discretionary access control (DAC) and mandatory access control (MAC). Since DAC and MAC are useful in information flow control (which protects privacy within an application), RBAC can certainly be used in that control. Our research reveals that different control granularity is needed in different cases when controlling information flows within an application. An information flow control model should thus simultaneously offer different levels of control granularity. We designed a multipleleveled RBAC model to offer multiple levels of control granularity, in which a level of RBAC controls a level of granularity. We called the model L n RBAC (n-leveled RBAC), which offer the following features: (1) it allows different control granularity in different cases, (2) it solves the covert channel problems caused by abnormal program stopping, (3) it adapts to dynamic object state change, (4) it controls method invocation through argument sensitivity (5) it allows purpose-oriented method invocation, (6) it controls write access precisely, and (7) it avoids Trojan horses. We implemented a prototype for L n RBAC and evaluated it. This paper presents L n RBACL.

Role-based access control (RBAC) is a promising alternative to traditional discretionary access control (DAC) and mandatory access control (MAC). The central idea of RBAC is that permissions are associated with roles, and users are made members of appropriate roles thereby acquiring the roles’ permissions. RBAC is policy neutral in that the precise policy being enforced is a consequence of how various components of RBACsuch as role hierarchies, constraints and administration of user-role and role-permission assignment-are configured. This raises the important question as to whether RBAC is sufficiently powerful to simulate DAC and MAC. Simulation of MAC in RBAC has been demonstrated earlier by Nyanchama and Osborn and by Sandhu. In this paper we demonstrate how to simulate several variations of DAC in RBAC, using the wellknown RBAC96 model of Sandhu et al. In combination with earlier work we conclude that RBAC encompasses both MAC and DAC.

Due to the enormous growth in the amount of digital information that needs to be stored, outsourcing data to third-party storage service providers, such as cloud, have attracted much attention in recent times. This has raised significant security issues such as how to control access to outsourced data stored on third-party sites. There have been many works on access control in the literature, and one of the well-known access control models is the role-based access control (RBAC), which provides flexible control and management by having two level mappings, users to roles and roles to privileges on data objects. Several cryptographic RBAC schemes have been proposed which integrate cryptographic techniques with RBAC models to enforce RBAC policies. In this paper, we develop the first generic constructions for cryptographic RBAC schemes which we refer to as role-based encryption (RBE) schemes. A RBE scheme allows data to be encrypted in such a way that only users with specific roles can decrypt the data. Hence, it can be used to enforce RBAC policies in an outsourcing environment. Our constructions use ID-based broadcast encryption (IBBE) techniques to build RBE schemes, and we show that the RBE scheme built from our generic constructions is secure if the selected IBBE scheme is secure. We also compare these constructions and analyse the advantages and disadvantages of each construction type.

In the past five years there has been tremendous activity in role-based access control (RBAC) models. Consensus has been achieved on a standard core RBAC model that is in process of publication by the US National Institute of Standards and Technology (NIST). An early insight was that RBAC cannot be encompassed by a single model since RBAC concepts range from very simple to very sophisticated. Hence a family of models is more appropriate than a single model. The NIST model reflects this approach. In fact RBAC is an open-ended concept which can be extended in many different directions as new applications and systems arise. The consensus embodied in the NIST model is a substantial achievement. All the same it just a starting point. There are important aspects of RBAC models, such as administration of RBAC, on which consensus remains to be reached. Recent RBAC models have studied newer concepts such as delegation and personalization, which are not captured in the NIST model. Applications of RBAC in workflow management systems have been investigated by several researchers. Research on RBAC systems that cross organizational boundaries has also been initiated. Thus RBAC models remain a fertile area for future research. In this paper we discuss some of the directions which we feel are likely to result in practically useful enhancements to the current state of art in RBAC models.KeywordsAccess ControlAccess Control ModelRBAC ModelMandatory Access ControlSpringer LNCSThese 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.

The increased complexity of modern access control (AC) systems stems partly from the need to support diverse and multiple administrative domains. Systems engineering is a key technology to manage this complexity since it is capable of assuring that an operational system will adhere to the initial conceptual design and defined requirements. Specifically, the verification stage of an AC system should be based on techniques that have a sound and mathematical underpinning. Working on this assumption, model checking techniques are applied for the verification of predefined system properties, and thus, conducting a security analysis of a system. In this paper, we propose the utilization of automated and error-free model checking techniques for the verification of security properties in multi-domain AC systems. Therefore, we propose a formal definition in temporal logic of four AC system properties regarding secure inter-operation with Role-Based Access Control (RBAC) policies in order to be verified by using model checking. For this purpose, we demonstrate the implementation of a tool chain for expressing RBAC security policies, reasoning on role hierarchies and properly feeding the model checking process. The proposed approach can be applied in any RBAC model to efficiently detect non-conformance between an AC system and its security specifications. As a proof of concept, we provide examples illustrating the verification of the defined secure inter-operation properties in multi-domain RBAC policies.

In the modern computing era, access to resources is often restricted through contextual information and the attributes of users, objects and various other entities. Attribute-Based Access Control (ABAC) can capture those requirements as a policy, but it is not yet adopted like Role Based Access Control (RBAC) due to lack of a comprehensive administrative model. In the last few years, several efforts have been made to combine ABAC with RBAC, but they are limited to specification and enforcement only. Recently, we have presented a unified framework along with a role based administrative model that enables specification, enforcement and maintenance of unified access control policies, such as ABAC, RBAC and Meta-Policy Based Access Control (MPBAC). This paper describes role-based administrative model components and then present a methodology which uses a fixed-point based approach for verifying the security properties (like safety and liveness) of those policies in the presence of the administrative model. We also analyse the impact of ABAC, RBAC, MPBAC and administrative model components on the time taken for security analysis. Experimental results demonstrate that the proposed approach is scalable as well as effective.

Dynamically monitoring the state changes of an underlying system, detecting and reacting to changes without delay are crucial for the success of any access control enforcement mechanism. With their inherent nature, active (Event- Condition-Action or ECA) rules are prospective candidates to carry out change detection and to provide access control. Current systems or models do not provide a flexible mechanism for enforcing Role-Based Access Control (RBAC) standard and its extensions in a seamless way, and do not adapt to policy or role structure changes in enterprises, which are indispensable to make RBAC usable in diverse domains. In this paper we will show how On-When-Then-Else authorization rules (or enhanced ECA rules) are used for enforcing RBAC standard and its extensions such as generalized temporal RBAC, control flow dependency constraints, privacy-aware RBAC, and so forth in a seamless way. Furthermore, these rules also provide active security. Large enterprises have hundreds of roles, which requires thousands of rules for providing access control, and generating these rules manually is error-prone and a cognitive-burden for non-computer specialists. Thus, in this paper, we will discuss briefly how these authorization rules can be automatically (or semi-automatically) generated from high level specifications of enterprise access control policies. We will also discuss the implementation using Sentinel+, an active object oriented system.

We propose an exception resolution service for a role based access control (RBAC) system as a supplementary service, that will increase the flexibility of RBAC systems. Our model will keep the security policies based on a RBAC system while some not role based administrations are possible. In other words, the not role based access permission is not independent from the RBAC system. The related definitions and functions are given. An implementation example shows that the service is useful and efficient in practice.