PANACEA: Tunable Privacy for Access Controlled Data in Peer-to-Peer Systems

Peer-to-peer paradigm is increasingly employed for organizing distributed resources for various applications, e.g. content distribution, open storage grid etc. In open environments, even when proper access control mechanisms supervise the access to the resources, privacy issues may arise depending on the application. In this paper, we introduce, PANACEA, a system that offers high and tunable privacy based on an innovative resource indexing approach. In our case, privacy has two aspects: the deduceability of a resource's existence/non-existence and the discovery of the provider of the resource. We systematically study the privacy that can be provided by the proposed system and compare its effectiveness as related to conventional P2P systems. Employing both probabilistic and information-theoretic approaches, we analytically derive that PANACEA can offer high privacy, while preserving high search efficiency for authorized users. Our analysis and the effectiveness of the approach have been experimentally verified. Moreover, the privacy offered by the proposed system can be tuned according to the specific application needs which is illustrated with detailed simulation study

Tunable Privacy for Access Controlled Data in Peer-to-Peer Systems

Peer-to-peer paradigm is increasingly employed for organizing distributed resources for various applications, e.g. content distribution, open storage grid etc. In open environments, even when proper access control mechanisms supervise the access to the resources, privacy issues may arise depending on the application. In this paper, we introduce, PANACEA, a system that offers high and tunable privacy based on an innovative resource indexing approach. In our case, privacy has two aspects: the deducibility of a resource's existence/non-existence and the discovery of the provider of the resource. We systematically study the privacy that can be provided by the proposed system and compare its effectiveness as related to conventional P2P systems. Employing both probabilistic and information-theoretic approaches, we analytically derive that PANACEA can offer high privacy, while preserving high search efficiency for authorized users. Our analysis and the effectiveness of the approach have been experimentally verified. Moreover, the privacy offered by the proposed system can be tuned according to the specific application needs which is illustrated with detailed simulation study

A Decentralized Online Social Network with Efficient User-Driven Replication

Unprecedented growth of online social networks (OSNs) increasingly makes privacy advocates and government agencies worrisome alike. In this paper, we propose My3, a privacy-friendly decentralized alternative for online social networking. The My3 system exploits well-known interesting properties of the current online social networks in its novel design namely, locality of access, predictable access times, geolocalization of friends, unique access requirements of the social content, and implicit trust among friends. It allows users to exercise finer granular access control on the content, thus making My3 extremely privacy-preserving. Moreover, we propose different replication strategies that users may independently choose for meeting their personalized performance objectives. A detailed performance study evaluates the system regarding profile availability, access delay, freshness and storage load. By using real-world data traces, we prove that My3 offers high availability even with low average online time of users in the network

Towards Access Control Aware P2P Data Management Systems

2P data management systems provide a scalable alternative to centralized architectures. Their adoption, however, is limited by the lack of possibility to control the access to the resources stored in the system. We address this problem in the case of structured P2P networks, in particular, when the system is used in a collaborative working environment. We analyze the problem assuming a simple threat model and we systematically explore the solution possibilities. We design and compare access control enforcement techniques which realize the desired functionality by constructing independent networks or by implementing access control at query or at response time