Secure and selective dissemination of XML documents

Abstract

XML (eXtensible Markup Language) has emerged as a prevalent standard for document representation and exchange on the Web. It is often the case that XML documents contain information of different sensitivity degrees that must be selectively shared by (possibly large) user communities. There is thus the need for models and mechanisms enabling the specification and enforcement of access control policies for XML documents. Mechanisms are also required enabling a secure and selective dissemination of documents to users, according to the authorizations that these users have. In this article, we make several contributions to the problem of secure and selective dissemination of XML documents. First, we define a formal model of access control policies for XML documents. Policies that can be defined in our model take into account both user profiles, and document contents and structures. We also propose an approach, based on an extension of the Cryptolope TM approach [Gladney and Lotspiech 1997], which essentially allows one to send the same document to all users, and yet to enforce the stated access control policies. Our approach consists of encrypting different portions of the same document according to different encryption keys, and selectively distributing these keys to the various users according to the access control policies. We show that the number of encryption keys that have to be generated under our approach is minimal and we present an architecture to support document distribution.

Secure Model Management Operations for the Web

“…Many proposals on access control mechanisms have been presented in both database literature [9,11,10,12,22] and XML area [3,5,7]. There are however few proposals on access controls across heterogeneous data models, and the most related works are those on secure XML federations [27] and XML security models using relational databases [13].…”

Supporting XML Security Models Using Relational Databases: A Vision

“…Recently, many access control methods extending the XML model to incorporate security aspects have been proposed (e.g., XACML [11], [6], [2], [23]). To the lesser or greater extent, however, such proposals neglect the fact that the most data for XML documents still reside in relational databases behind the scenes, and consequently do not utilize various security models that have been proposed for and implemented in relational databases.…”

“…In [6], the model proposed in [7] is extended by enriching the authorization types supported by the model, providing a complete description of the specification and enforcement mechanism. Among comparable proposals, in [2], an access control environment for XML documents and some techniques to deal with authorization priorities and conflict resolution issues are proposed. Finally, the use of authorization priorities with propagation and overriding, which is an important aspect of XML access control may recall approaches in the context of object-oriented databases, like [9] and [18].…”

Security-Conscious XML Indexing

“…Recently, many proposals focusing on XML security models or enforcement mechanisms have appeared (e.g., XACML, [3], [1]). However, XML query processing issues using indices in dealing with secure XML data has gotten little attention.…”

“…[3] extends [4] by enriching the supported authorization types, providing a complete description of specification and enforcement mechanism. In [1], an access control environment for XML documents and techniques to deal with authorization priorities and conflict resolution issues are proposed. We base our approach on XISS [6].…”