A Formal Study of Collaborative Access Control in Distributed Datalog

VCLA will host a talk by Pierre Bourhis on Thursday, February 18, 2016.

ABSTRACT

We formalize and study a declaratively specified collaborative access control mechanism for data dissemination in a distributed environment. Data dissemination is specified using distributed datalog. Access control is also defined by datalog-style rules, at the relation level for extensional relations, and at the tuple level for intensional ones, based on the derivation of tuples. The model also includes a mechanism for “declassifying” data, that allows circumventing overly restrictive access control. We consider the complexity of determining whether a peer is allowed to access a given fact, and address the problem of achieving the goal of disseminating certain information under some access control policy. We also investigate the problem of information leakage, which occurs when a peer is able to infer facts to which the peer is not allowed access by the policy. Finally, we consider access control extended to facts equipped with provenance information, motivated by the many applications where such information is required. We provide semantics for access control with provenance, and establish the complexity of determining whether a peer may access a given fact together with its provenance. This work is motivated by the access control of the Webdamlog system, whose core features it formalizes. Pierre Bourhis is a junior researcher at CNRS in the department of computer science signal and automatism CRIStAL at Lille. He is a member of the team "Links" belonging to INRIA Lille CRIStAL. Pierre completed his PhD at the University of South Paris on the dynamic of active documents under the supervision of Serge Abiteboul, which followed by a post-doctorate under the supervision of Michael Benedikt at the University of Oxford. His main research topics include theory of database and more recently knowledge representation. Pierre has published in the top conferences in these fields (PODS, ICDT, VLDB, ICDE, IJCAI, KR) and the theory of computer science (ICALP), as well as in the main journal of database (TODS). Recently, his paper ‘Reasonable Highly Expressive Query Languages’, co-written with Sebastian Rudoph and Markus Krötzsch, was a distinguished paper (honorary mention) in IJCAI 2015. Additionally, Pierre is the secretary of the French PhD prize Gilles Kahn committee.