Building Confidential and Efficient Query Services in the Cloud with RASP Data Perturbation

With the wide deployment of public cloud computing infrastructures, using clouds to host data query services has become an appealing solution for the advantages on scalability and cost-saving. However, some data might be sensitive that the data owner does not want to move to the cloud unless the data confidentiality and query privacy are guaranteed. On the other hand, a secured query service should still provide efficient query processing and significantly reduce the in-house workload to fully realize the benefits of cloud computing. We propose the RASP data perturbation method to provide secure and efficient range query and kNN query services for protected data in the cloud. The RASP data perturbation method combines order preserving encryption, dimensionality expansion, random noise injection, and random projection, to provide strong resilience to attacks on the perturbed data and queries. It also preserves multidimensional ranges, which allows existing indexing techniques to be applied to speedup range query processing. The kNN-R algorithm is designed to work with the RASP range query algorithm to process the kNN queries. We have carefully analyzed the attacks on data and queries under a precisely defined threat model and realistic security assumptions. Extensive experiments have been conducted to show the advantages of this approach on efficiency and security.Comment: 18 pages, to appear in IEEE TKDE, accepted in December 201

Protecting sensitive data using differential privacy and role-based access control

Dans le monde d'aujourd'hui où la plupart des aspects de la vie moderne sont traités par des systèmes informatiques, la vie privée est de plus en plus une grande préoccupation. En outre, les données ont été générées massivement et traitées en particulier dans les deux dernières années, ce qui motive les personnes et les organisations à externaliser leurs données massives à des environnements infonuagiques offerts par des fournisseurs de services. Ces environnements peuvent accomplir les tâches pour le stockage et l'analyse de données massives, car ils reposent principalement sur Hadoop MapReduce qui est conçu pour traiter efficacement des données massives en parallèle. Bien que l'externalisation de données massives dans le nuage facilite le traitement de données et réduit le coût de la maintenance et du stockage de données locales, elle soulève de nouveaux problèmes concernant la protection de la vie privée. Donc, comment on peut effectuer des calculs sur de données massives et sensibles tout en préservant la vie privée. Par conséquent, la construction de systèmes sécurisés pour la manipulation et le traitement de telles données privées et massives est cruciale. Nous avons besoin de mécanismes pour protéger les données privées, même lorsque le calcul en cours d'exécution est non sécurisé. Il y a eu plusieurs recherches ont porté sur la recherche de solutions aux problèmes de confidentialité et de sécurité lors de l'analyse de données dans les environnements infonuagique. Dans cette thèse, nous étudions quelques travaux existants pour protéger la vie privée de tout individu dans un ensemble de données, en particulier la notion de vie privée connue comme confidentialité différentielle. Confidentialité différentielle a été proposée afin de mieux protéger la vie privée du forage des données sensibles, assurant que le résultat global publié ne révèle rien sur la présence ou l'absence d'un individu donné. Enfin, nous proposons une idée de combiner confidentialité différentielle avec une autre méthode de préservation de la vie privée disponible.In nowadays world where most aspects of modern life are handled and managed by computer systems, privacy has increasingly become a big concern. In addition, data has been massively generated and processed especially over the last two years. The rate at which data is generated on one hand, and the need to efficiently store and analyze it on the other hand, lead people and organizations to outsource their massive amounts of data (namely Big Data) to cloud environments supported by cloud service providers (CSPs). Such environments can perfectly undertake the tasks for storing and analyzing big data since they mainly rely on Hadoop MapReduce framework, which is designed to efficiently handle big data in parallel. Although outsourcing big data into the cloud facilitates data processing and reduces the maintenance cost of local data storage, it raises new problem concerning privacy protection. The question is how one can perform computations on sensitive and big data while still preserving privacy. Therefore, building secure systems for handling and processing such private massive data is crucial. We need mechanisms to protect private data even when the running computation is untrusted. There have been several researches and work focused on finding solutions to the privacy and security issues for data analytics on cloud environments. In this dissertation, we study some existing work to protect the privacy of any individual in a data set, specifically a notion of privacy known as differential privacy. Differential privacy has been proposed to better protect the privacy of data mining over sensitive data, ensuring that the released aggregate result gives almost nothing about whether or not any given individual has been contributed to the data set. Finally, we propose an idea of combining differential privacy with another available privacy preserving method

TOP-K QUERY DISPENSATION IN SECURE SPATIAL ENVIRONMENT VIA UNTRUSTED LOCATION-BASED SERVICE PROVIDERS

IN Collaborative location-based information generation and sharing is considered, which become increasingly popular due to the explosive growth of Internet-capable and location-aware mobile devices. The system consists of a data collector, data contributors, location-based service providers (LBSPs), and system users. The data collector gathers reviews about points-of-interest (POIs) from data contributors, while LBSPs purchase POI data sets from the data collector and allow users to perform spatial top-k queries which ask for the POIs in a certain region and with the highest k ratings for an interested POI attribute. In practice, LBSPs are untrusted and may return fake query results for various bad motives, e.g., in favor of POIs willing to pay. Three novel schemes is used for users to detect fake spatial snapshot and moving top-k query results as an effort to foster the practical deployment and use of the proposed system

LightBox: Full-stack Protected Stateful Middlebox at Lightning Speed

Running off-site software middleboxes at third-party service providers has been a popular practice. However, routing large volumes of raw traffic, which may carry sensitive information, to a remote site for processing raises severe security concerns. Prior solutions often abstract away important factors pertinent to real-world deployment. In particular, they overlook the significance of metadata protection and stateful processing. Unprotected traffic metadata like low-level headers, size and count, can be exploited to learn supposedly encrypted application contents. Meanwhile, tracking the states of 100,000s of flows concurrently is often indispensable in production-level middleboxes deployed at real networks. We present LightBox, the first system that can drive off-site middleboxes at near-native speed with stateful processing and the most comprehensive protection to date. Built upon commodity trusted hardware, Intel SGX, LightBox is the product of our systematic investigation of how to overcome the inherent limitations of secure enclaves using domain knowledge and customization. First, we introduce an elegant virtual network interface that allows convenient access to fully protected packets at line rate without leaving the enclave, as if from the trusted source network. Second, we provide complete flow state management for efficient stateful processing, by tailoring a set of data structures and algorithms optimized for the highly constrained enclave space. Extensive evaluations demonstrate that LightBox, with all security benefits, can achieve 10Gbps packet I/O, and that with case studies on three stateful middleboxes, it can operate at near-native speed.Comment: Accepted at ACM CCS 201