Privacy-preserving policy evaluation in multi-party access control

Recent years have seen an increasing popularity of online collaborative systems like social networks and web-based collaboration platforms. Collaborative typically offer their users a digital environment in which they can work together share resources information. These information might be sensitive and, thus, should protected from unauthorized accesses. Multi-party access control is emerging as new paradigm for the protection co-owned co-managed resources, where policies all involved management resource accounted decision making. Existing approaches, however, only focus on jointly do not address individual user themselves, whose disclosure leak In this work, we propose privacy-preserving mechanism evaluation multi-party policies, preserves confidentiality while remaining capable making decisions. To end, design secure computation protocols form against query realize such using two techniques, namely Homomorphic Encryption Secure Functional Evaluation. We show practical feasibility our terms communication costs through experimental evaluation.