Yu / Jajodia Secure Data Management in Decentralized Systems

1. Auflage 2007
ISBN: 978-0-387-27696-0
Verlag: Springer US
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 33, 462 Seiten, eBook

Reihe: Advances in Information Security

Database security is one of the classical topics in the research of information system security. Ever since the early years of database management systems, a great deal of research activity has been conducted. Fruitful results have been produced, many of which are widely adopted in commercial and military database management systems. In recent years, the research scope of database security has been greatly expanded due to the rapid development of the global internetworked infrastructure. Databases are no longer stand-alone systems that are only accessible to internal users of - ganizations. Instead, allowing selective access from different security domains has become a must for many business practices. Many of the assumptions and problems in traditional databases need to be revisited and readdressed in decentralized en- ronments. Further, the Internet and the Web offer means for collecting and sharing data with unprecedented flexibility and convenience. New data services are eme- ing every day, which also bring new challenges to protect of data security. We have witnessed many exciting research works toward identifying and addressing such new challenges. We feel it is necessary to summarize and systematically present works in these new areas to researchers. This book presents a collection of essays, covering a wide range of today's active areas closely related to database security organized as follows. In Part I, We review classical work in database security, and report their recent advances and necessary extensions.

Zielgruppe

Professional/practitioner

Autoren/Hrsg.

Yu, Ting

Jajodia, Sushil

Inhaltsverzeichnis

Foundation.- Basic Security Concepts.- Access Control Policies and Languages in Open Environments.- Trusted Recovery.- Access Control for Semi-Structured Data.- Access Control Policy Models for XML.- Optimizing Tree Pattern Queries over Secure XML Databases.- Distributed Trust Management.- Rule-based Policy Specification.- Automated Trust Negotiation in Open Systems.- Building Trust and Security in Peer-to-Peer Systems.- Privacy in Cross-Domain Information Sharing.- Microdata Protection.- ?-Anonymity.- Preserving Privacy in On-line Analytical Processing Data Cubes.- Security in Emerging Data Services.- Search on Encrypted Data.- Rights Assessment for Relational Data.

Leseproben

2 Security Policy (p. 4)

The security policy elaborates on each of the three generic objectives of security- secrecy, integrity, and availability-in the context of a particular system. Thus, com- puter security policies are used like requirements, they are the starting point in the development of any system that has security features. The security policy of a system is the basis for the choice of its protection mechanisms and the techniques used to assure its enforcement of the security policy.

Existing security policies tend to focus only on the secrecy requirement of se- curity. Thus, these policies deal with defining what is authorized or, more simply, arriving at a satisfactory definition of the secrecy component. The choice of a security policy with reasonable consequences is nontrivial and a separate topic in its own right. In fact, security policies are investigated through formal mathematical models. These models have shown, among other things, that the consequences of arbitrary but relatively simple security policies are undecidable and that avoiding this undecidability is nontrivial [5,7,8]. To read more about the formal security models, see [3].

All security policies are stated in terms of objects and subjects. This is because in reasoning about security policies, we must be careful about the distinction between users and the processes that act on behalf of the users. Users are human beings that are recognized by the system as users with an unique identity. This is achieved via identification and authentication mechanisms, the familiar example is a user identi- fier and password.

All system resources are abstractly lumped together as objects and, thus, all ac- tivities within a system can be viewed as sequences of operations on objects. In the relational database context, an object may be a relation, a tuple within a relation, or an attribute value within a tuple. More generally, anything that holds data may be an object, such as memory, directories, interprocess messages, network packets, I10 devices, or physical media.

A subject is an abstraction of the active entities that perform computation in the system. Thus, only subjects can access or manipulate objects. In most cases, within the system a subject is usually a process, job, or task, operating on behalf of some user, although at a higher level of abstraction users may be viewed as subjects. A user can have several subjects running in the system on his or her behalf at the same time, but each subject is associated with only a single user. This requirement is important to ensure the accountability of actions in a system.

Although the subject-object paradigm makes a clear distinction between subjects and objects (subjects are active entities, while objects are passive entities), an entity could be both a subject and an object. The only requirement is that if an entity be- haves like a subject (respectively, object), it must abide by rules of the model that apply to subjects (respectively, objects).

Basic Security Concepts 5

The reason a distinction must be made between users and subjects is that while users are trusted not to deliberately leak information (they do not require a computer system to do so), subjects initiated by the users cannot be trusted to always abide by the security policy.