Privacy Preserving Queries on Directed Graph

In this work, a trust relation determines whether a certain user (at source-host) has permission to access another user (at target-host) by utilising an authentication key with unique fingerprint F. These trust relations can be interpreted as a directed graph, where nodes are user-host pairs and edges are fingerprints. We study the problem of constructing a privacy preserving trust relation data structure. Moreover, we design and prototype a querying mechanism for this data structure and show that it is feasible in practice. We validate our design by utilising real world data.