ObliviSync: Practical Oblivious File Backup and Synchronization

Oblivious RAM (ORAM) protocols are powerful techniques that hide a client's data as well as access patterns from untrusted service providers. We present an oblivious cloud storage system, ObliviSync, that specifically targets one of the most widely-used personal cloud storage paradigms: synchronization and backup services, popular examples of which are Dropbox, iCloud Drive, and Google Drive. This setting provides a unique opportunity because the above privacy properties can be achieved with a simpler form of ORAM called write-only ORAM, which allows for dramatically increased efficiency compared to related work. Our solution is asymptotically optimal and practically efficient, with a small constant overhead of approximately 4x compared with non-private file storage, depending only on the total data size and parameters chosen according to the usage rate, and not on the number or size of individual files. Our construction also offers protection against timing-channel attacks, which has not been previously considered in ORAM protocols. We built and evaluated a full implementation of ObliviSync that supports multiple simultaneous read-only clients and a single concurrent read/write client whose edits automatically and seamlessly propagate to the readers. We show that our system functions under high work loads, with realistic file size distributions, and with small additional latency (as compared to a baseline encrypted file system) when paired with Dropbox as the synchronization service.Comment: 15 pages. Accepted to NDSS 201

Efficient Oblivious Data Structures for Database Services on the Cloud

Database-as-a-service (DBaaS) allows the client to store and manage structured data on the cloud remotely. Despite its merits, DBaaS also brings significant privacy issues. Existing encryption techniques (e.g., SQL-aware encryption) can mitigate privacy concerns, but they still leak information through access patterns, which are vulnerable to statistical inference attacks. Oblivious Random Access Machine (ORAM) can seal such leakages; however, the recent studies showed significant challenges on the integration of ORAM into databases. That is, the direct usage of ORAM on databases is not only costly but also permits very limited query functionalities. In this paper, we propose new oblivious data structures called Oblivious Matrix Structure (OMAT) and Oblivious Tree Structure (OTREE), which allow tree-based ORAM to be integrated into database systems in a more efficient manner with diverse query functionalities supported. OMAT provides special ORAM packaging strategies for table structures, which not only offers a significantly better performance but also enables a broad range of query types that may not be efficient in existing frameworks. On the other hand, OTREE allows oblivious conditional queries to be performed on tree-indexed databases more efficiently than existing techniques. We implemented our proposed techniques and evaluated their performance on a real cloud database with various metrics, compared with state-of-the-art counterparts

Decision-making and ante-natal screening for sickle cell and thalassaemia disorders : To what extent do faith and religious identity mediate choice?

When making decisions about prenatal diagnosis, couples not only draw on their understanding of the condition but also broader aspects of their cultural identity. This article looks at how faith and religion mediate attitudes towards screening, prenatal diagnosis and termination of pregnancy for sickle cell and thalassaemia disorders. The article specifically reports on a qualitative study, which used focus groups from a variety of faith communities (Muslim, Sikh, Hindu and Christian), at risk of haemoglobin disorders, living in England. Our findings suggest that the decision about whether or not to have diagnostic testing generally related to attitudes towards the termination of pregnancy. The consequences of the condition were as important as religious beliefs to most people. More generally, faith beliefs emerged as negotiable and contingent: realized within a broader moral framework. Religion was felt not to be prescriptive and reproductive decisions were seen as personal. When making decisions, people utilize faith within a broader context of individual, family and social relationships

Dynamic analysis of an institutional conflict within the music industry

Peer-to-peer technology has made massive music piracy possible, which, in turn, has arguably had a significant economic impact on the recording industry. Record labels have responded to online piracy with litigation and are also considering self-help measures. It is currently not obvious whether or not these counter-piracy strategies will ultimately stifle online file sharing in the long term. With this paper we attempt to add to our understanding of the conflict within the institution that is the commercial music industry. We conduct an institutional analysis of the industry in transition and extend the traditional pattern modeling methodology with a formal resource-based model of a representative online music network. The model accounts for complex causal interactions between resources, private provision of common goods, free riding and membership dynamics. The numerical implementation of the model is the basis of a decision support system, which is used in a series of computer experiments that emulate anti-piracy scenarios. We show that a peer-to-peer system may be quite resilient to outside disturbances. The experiments also demonstrate that policies rank differently in their effectiveness based on a selected yardstick.Peer-to-peer (P2P) networks; Online File Sharing; Copyright; Simulation

Completion Report of the Asian Agricultural Research Project (Contract No. AID/ASIA-C-1456)

Research and Development/Tech Change/Emerging Technologies,