Towards Dynamically Administered Role-Based Access Control Andreas K. Mattas 1 , Ioannis K. Mavridis 2 and George I. Pangalos 1 1 Aristotle University of Thessaloniki, Greece, mattman@gen.auth.gr, pangalos@gen.auth.gr 2 University of Macedonia, Thessaloniki, Greece, mavridis@uom.gr Abstract In digital business, the need for efficient frameworks to address the multifaceted security issues related to Web- based applications, has led to efforts towards the development of dynamically administered access control systems that implement robust access control models, to allow controlled access of information based on content or context of processing, and secure interoperation in a dynamic distributed enterprise environment. Pure RBAC seems to be suitable for function-oriented organization structures usually used in relatively stable environments. On the other hand, TBAC and TMAC provide a complementary support in environments that are based on process-oriented organization structures. However, current organizational alternatives lead to the combination of the above approaches, in the form of a matrix organization structure that maximizes the advantages of functional and process-oriented structures and introduces the need for new access control administration paradigms. In this paper we discuss our approach for dynamically administered role-based access control, which covers the need-to-know requirements of users and missions are involved with, and provides tight and just-in-time access control without sacrificing operability and simplicity of administration. 1. Introduction Today’s organizations focus on establishing more trust in online environments in order to encourage more people to do digital business and to seek services over the Web. However, trust and trustworthiness are the foundations of security services [1]. Two classes of main security services are the basis for a secure Internet infrastructure; access control services and communication security services. The latter guaranties the integrity and confidentiality of the information transmitted over the network. The former ensures that information is not accessed or manipulated by unauthorized persons. Solutions used in this context include public-key technologies incorporating solutions using access control models such as role based access control (RBAC) [2]. Insider attacks constitute a considerable threat, which elevates the need for robust access control services in organizations. Security models that allow efficient security administration must also be extended for multi domain environments. For the Web, access mechanisms should facilitate dynamic changes in the content and context of information, allow monitoring of the state of the system, and facilitate the carrying out transactional activities. Existing access models lack these features [1]. Pure RBAC [3] seems to be suitable for function- oriented hierarchical organization structures (vertical approach) usually used in relatively stable environments. On the other hand, task-based authorization controls (TBAC) [4] and team-based access control (TMAC) [5] provide a complementary support for access control in environments requiring flexibility and are based on project-oriented organization structures (horizontal approach), where the concepts of task and team are gaining a central role [6], [7]. However, current organizational alternatives lead to the combination of the above approaches towards a matrix organization structure. Taking into consideration the above ascertainments, it becomes apparent that digital business can be fully supported by a trust management system that is based on an active and dynamically administered access control system, which satisfies at a high granularity level the security principle of least-privilege without sacrificing operability and simplicity of administration. In this paper we present our approach on this direction called the DARBAC model (Dynamically Administered Role-based Access Control), which uses a set of dynamic administration mechanisms that makes it suitable for a computing environment such as the Internet. 2. Limitations of the Administration Characteristics in Classical Access Control Access control administration can be performed in various ways depending on the specific access control model used. Classical access control administration varies between centralized approaches to flexible but excessively decentralized ones [8]. Proceedings of the 14th International Workshop on Database and Expert Systems Applications (DEXA’03) 1529-4188/03 $17.00 © 2003 IEEE