Constructing Inference-Proof Belief Mediators

Abstract

Abstract. An information owner might interact with cooperation partners regarding its belief, which is derived from a collection of heterogeneous data sources and can be changed according to perceptions of the partners' actions. While interacting, the information owner willingly shares some information with a cooperation partner but also might want to keep selected pieces of information confidential. This requirement should even be satisfied if the partner as an intelligent and only semi-honest attacker attempts to infer hidden information from accessible data, also employing background knowledge. For this problem of inference control, we outline and discuss a solution by means of a sophisticated mediator agent. Based on forming an integrated belief from the underlying data sources, the design adapts and combines known approaches to language-based information flow control and controlled interaction execution for logic-based information systems.

Confidentiality enforcement by hybrid control of information flows

“…For the same reason, all other arguments of the FlowTracker's computation eval(transToSym(transToET(hp), Γ ))(tempvs, mem low ) in (r, t start ) and (r , t start ) are equal (the low memory due to state agreement low). So, we showed (8) and the equality in (9).…”

“…This conviction led us to spending much effort to find and exploit established methods for solutions of the four tasks. Research fields supporting our efforts include information system integration and mediation [15], data-program interfacing [16], logic-based inference control [5] and language-based information flow control with declassification [25] as further discussed in [9].…”

“…In this case, the confidentiality policy could be stated more conveniently as a set of logical sentences and Asumption 2 can be established by results on view computations for particular basic information requests, including queries to relational databases or incomplete databases, updates, see the summaries [5,6] and revisions [10]. Such requests can be jointly offered by information mediation, to be integrated into our framework as outlined in [9].…”

“…Regarding the domain in (9) and the equivalence of (10), we will consider the execution tree T generated from hp preserving the one-step semantics. Moreover, we will consider the memory mem n produced by T after processing a node n and all expressions expr defined over high variables and over expressions in the image of init.…”