Formal Description of Trust-based Access Control

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.

ABSTRACTSome specific information or resources only can be accessed by authorized users. Discretionary access control (DAC), mandatory access control (MAC), and role‐based access control (RBAC) are three main classes of access control policies. MAC and RBAC are more secure than discretionary access control because a system instead of an object's owner determines the policy. MAC is appropriate for multilevel applications with high security requirements such as military ones, while RBAC provides security and business benefits. Most institutions, companies, and governments are multilevel, so relationships between roles or security levels tend to be hierarchical. In this work, an access control mechanism, providing explicit transitive exception and antisymmetric arrangement, is proposed to provide flexible and appropriate solutions to hierarchical relationships. For practicability, no access control policy is strictly constrained in the proposed mechanism such that security classes can be determined according to specific requirements. The proposed mechanism employs an elliptic curve cryptosystem and a two‐layer hash approach to ensure security and computation efficiency. Copyright © 2014 John Wiley & Sons, Ltd.

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.

Towards more pro-active access control in computer systems and networks

Access control is generally a rule or procedure that allows, denies, restricts or limit access to system's resources. It may, as well, monitor and record all attempts made to access a system. Access Control may also identify users attempting to access unauthorized resources. It is a mechanism which is very much important for protection in computer security. Various access control models are in use, including the most common Mandatory Access Control (MAC), Discretionary Access Control (DAC) and Role Based Access Control (RBAC). All these models are known as identity based access control models. In all these access control models, user (subjects) and resources (objects) are identified by unique names. Identification may be done directly or through roles assigned to the subjects. These access control methods are effective in unchangeable distributed system, where there are only a set of Users with a known set of services. For this reason, we propose a framework which is well suited to many situations in cloud computing where users or applications can be clearly separated according to their job functions. In this chapter, we proposes a role based access control framework with various features including security of sensitive data, authorization policy and secure data from hackers. Our proposed role based access control algorithm provides tailored and fine level of user access control services without adding complexity, and supports access privileges updates dynamically when a user's role is added or updated.

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 (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.

Access control is a security technique that specifies which users can access particular resources in a computing environment. Over the years, numerous access control models have been developed to address various aspects of computer security. In this paper, we focus on a modern approach, attribute-based access control (ABAC), which has been proposed in order to overcome limitations of traditional models: discretionary access control (DAC), mandatory access control (MAC) and role-based access control (RBAC). The work on integrating access control mechanisms in semantic web technologies is developing into two directions: (1) to use semantic web technologies for modeling and analyzing access control policies and (2) to protect knowledge encoded in an ontology. In this paper we focus on the first issue and investigate how ABAC can be integrated into ontology languages.

With the increasingly strict requirement for computer system security, access control models have become more complex. Existing models, such as discretionary access control (DAC) model, mandatory access control (MAC) model, role based access control (RBAC) model, and attribute based access control (ABAC) model, all have advantages and disadvantages regarding practicability and security. In addition, there is an inherent security risk in these access control models. The models merely control the access permission, but ignore the verification for the identity credibility of the entities involved in the access. With the proposal of trusted computing and the application of trusted platform, it is possible to implement, on stand-alone computers, the verification of identity credibility for the entities involved in the access. In this paper, we analyze the authorization and access decision policy of the RBAC model and the ABAC model. The characteristics of the trusted computing, which can ensure the identity credibility of the entities involved in the access, is also considered. Based on the above analysis, we establish a trusted computing based enhanced access control (TCBEAC) model, which can be deployed on stand-alone computers for common users.

An access control system is a collection of rules used to restrict the visibility, access, and usage of the data resources in an institutional environment. When implemented, these rules provide a policy for achieving the security of the institution, establishing a hierarchy of the employees depending on their rights over the institution’s data resouces. An access control system is based on two fundamental concepts: authentication (that verifyies the user's identity) and authorization (that provides a hierarchy of the employees according to their access rights over the institutional resources). Among the most commonly used access control models we recall Role-Based Access Control (RBAC), in which users with the same role have equal access rights to data resources, Discretionary Access Control (DAC), in which the system owner decides which user has access to system resources, and Mandatory Access Control (MAC), in which a series of rules, with a high level of security established by a predefined authority, are used. In this article, we will study the last two models, namely DAC and MAC, along with their main implementations: Access Control Matrix and the Take-Grant models for DAC, BIBA and Bell-LaPadula for MAC.

Chapter 5 - Domain 5: Identity and access management (controlling access and managing identity)

Nowadays the enterprise informatization is more and more important in the development of an enterprise. With the development of enterprises' informatization construction, more attention than ever before is paid to the security of information management RBAC, as a substitute of traditional access control mechanism Discretionary Access Control (DAC) and Mandatory Access Control (MAC), the concept can meet the application of enterprise-level's access control management which have more users and different role systems. RBAC can protect the enterprise information from danger.

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>

Many existing software systems like logistics systems or enterprise applications employ data security in a more or less ad hoc fashion. Our approach focuses on access control such as permission-based discretionary access control (DAC), variants of role-based access control (RBAC) with delegation, and attribute-based access control (ABAC). Typically, software systems implement hybrid access control making an effective security analysis and assessment rather difficult. We propose an analysis methodology to reconstruct access control using a novel modular access control model. Our modular approach allows us to flexibly model exactly those access properties that are relevant for a given system. As formalism we use the Object Constraint Language (OCL) with Ecore from the Eclipse Modeling Framework (EMF). We demonstrate the suitability of our access control model for three software systems: a port community system (PCS), a clinical information system (CIS), and an identity management system (IdMS). For the PCS and CIS we model concrete roles and policies. For the IdMS we evaluate our analysis methodology in-depth by reconstructing access control policies from byte code using the Soot analysis framework as well as model transformation techniques (QVTo). The resulting model helped us to identify design deficiencies. Violated OCL invariants such as for mutually exclusive roles or cardinality constraints revealed non-trivial security vulnerabilities.

The traditional mandatory access control policy (MAC) is regarded as a policy with strict regulation and poor flexibility. The security policy of MAC is so compelling that few information systems would adopt it at the cost of facility, except some particular cases with high security requirement as military or government application. However, with the increasing requirement for flexibility, even some access control systems in military application have switched to role-based access control (RBAC) which is well known as flexible. Though RBAC can meet the demands for flexibility but it is weak in dynamic authorization and consequently can not fit well in the workflow management systems. The task-role-based access control (T-RBAC) is then introduced to solve the problem. It combines both the advantages of RBAC and task-based access control (TBAC) which uses task to manage permissions dynamically. To satisfy the requirement of system which is distributed, well defined with workflow process and critically for time accuracy, this paper will analyze the spirit of MAC, introduce it into the improved T&RBAC model which is based on T-RBAC. At last, a conceptual task-role-based access control model with high security for distributed workflow and real-time application (A_T&RBAC) is built, and its performance is simply analyzed.