Selective and authentic third-party distribution of XML documents

Abstract

Third-party architectures for data publishing over the Internet today are receiving growing attention, due to their scalability properties and to the ability of efficiently managing large number of subjects and great amount of data. In a third-party architecture, there is a distinction between the Owner and the Publisher of information. The Owner is the producer of information, whereas Publishers are responsible for managing (a portion of) the Owner information and for answering subject queries. A relevant issue in this architecture is how the Owner can ensure a secure and selective publishing of its data, even if the data are managed by a third-party, which can prune some of the nodes of the original document on the basis of subject queries and access control policies. An approach can be that of requiring the Publisher to be trusted with regard to the considered security properties. However, the serious drawback of this solution is that large Web-based systems cannot be easily verified to be secure and can be easily penetrated. For these reasons, in this paper, we propose an alternative approach, based on the use of digital signature techniques, which does not require the Publisher to be trusted. The security properties we consider are authenticity and completeness of a query response, where completeness is intended with regard to the access control policies stated by the information Owner. In particular, we show that, by embedding in the query response one digital signature generated by the Owner and some hash values, a subject is able to locally verify the authenticity of a query response. Moreover, we present an approach that, for a wide range of queries, allows a subject to verify the completeness of query results.

Privacy Preserving Context Aware Publish Subscribe Systems

“…Secure content based pub/sub systems: Privacy and confidentiality issues in pub/sub systems have long been identified [28], but little progress has been made to address these issues in a holistic manner. Most of prior work on data confidentiality techniques in the context of content based pub/sub systems is based on the assumption that brokers are trusted with respect to the privacy of the subscriptions by subscribers [2,27,16]. However, when such an assumption does not hold, both publication confidentiality and subscription privacy are at risk.…”

Authenticating the query results of text search engines

“…The first methods on authentication of outsourced databases belong to the first category and build upon the MHT (e.g. [8,20,2]). [13] proposed the most complete and efficient MHT-based method to date, called Embedded Merkle B-tree (EMB-tree).…”

“…With the chain-MHT, the VO for a query result contains the signature of every query term's inverted list 2 . When the query processing algorithm terminates, all the processed document identifiers in the inverted lists of the query terms are also added to the VO.…”

Verified Query Results from Hybrid Authentication Trees

“…Devanbu, et al described authentication for queries on XML document collections in [5]. Bertino, et al focus in detail on XML documents in [3] and leverage access control mechanisms as a means of providing client proofs of completeness. They also expand supported query types and provide a detailed investigation of XML authentication issues including updates, and address important implementation issues.…”