In this paper, we focus on a framework of multilevel security databases. We assume subjects form a hierarchy and they have varying beliefs about existence, identities, and other properties of objects. Every subject has an object space that represents its own belief about the real world. A subject is interested in not only query of objects in its own space, but also how they relate to objects be...

Many multilevel relational data models have been proposed, and diierent models ooer diierent advantages. In this paper, we adapt and reene several of the best ideas from previous models and add new ideas to build the new Multilevel Relational (MLR) data model. MLR provides multilevel relations with element-level labeling, as a natural extension of the traditional relational data model. MLR intr...

The problem of multilevel diversity coding with secure regeneration (MDC-SR) is considered, which includes the problems of multilevel diversity coding with regeneration (MDC-R) and secure regenerating code (SRC) as special cases. Two outer bounds are established, showing that separate coding of different messages using the respective SRCs can achieve the minimum-bandwidth-regeneration (MBR) poi...

Much research has been done in the area of multilevel database systems, especially in the security area and accelerating queries. In this paper, we present BVA, which is based on bit vectors to accelerate queries in multilevel secure database systems. As its predecessor (BVA), the BVA algorithm follows the classic Sea View Model, but it recovers query output from single-level relations in a fas...

In this paper, we consider multilevel relations in which security classi cations are assigned at the granularity of individual data elements. Usually these multilevel relations exist only at the logical level. In reality, a multilevel relation is decomposed into a collection of single level base relations which are then physically stored in a database, and a recovery algorithm is used to recons...

Workflow management systems (WFMS) support the modeling and coordinated execution of processes within an organization. To coordinate the execution of the various activities (or tasks) in a workflow, task dependencies are specified among them. As advances in workflow management take place, they are also required to support security. In a multilevel secure (MLS) workflow, tasks may belong to diff...

African regional organizations’ increasing activity in security policy is usually approached through the concept of a ‘security community’, which can only partially clarify their difficult situation. A multilevel governance model is suggested as a more useful approach in a situation where economic cooperation is weak, member states’ principles of governance diverge, and they themselves might be...

Web based work ows are increasingly becoming a viable choice for work ows that span multiple organizations Until recently Web technology has not been terribly secure However by utiliz ing appropriate encryption algorithms digital signatures and access control role based multilevel security Web based Work ow Management Systems can be made secure Since these systems include many subsystems Operat...

We discuss a class of computer/network architectures that supports multilevel security while utilizing commercial-off-the-shelf (COTS) workstations and COTS productivity software applications. We show that a property of these architectures is that, while supporting multilevel confidentiality policies, they do not generally support partially ordered integrity policies: specifically, these archit...

Workkow management systems (WFMS) support the modeling and coordinated execution of processes within an organization. As advances in workkow management take place, they are also required to support security. This paper makes two major contributions to the area of workkow management. First, it shows how both mandatory and discretionary security can be incorporated into WFMS. Second, it provides ...