Browsing by Author "Eryonucu, Cihan"

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Bir şehir, bir gitar, bir insan : Süleyman Bağcıoğlu
(Bilkent University, 2015) Eryonucu, Cihan; Aydın, Muhammed Safa; Harmankaya, Muhammed Selahaddin; Özilhan, Doğan Berk; Katnaş, Sedat
Open Access
A demonstration of privacy-preserving aggregate queries for optimal location selection
(IEEE, 2018) Eryonucu, Cihan; Ayday, Erman; Zeydan, E.
In recent years, service providers, such as mobile operators providing wireless services, collected location data in enormous extent with the increase of the usages of mobile phones. Vertical businesses, such as banks, may want to use this location information for their own scenarios. However, service providers cannot directly provide these private data to the vertical businesses because of the privacy and legal issues. In this demo, we show how privacy preserving solutions can be utilized using such location-based queries without revealing each organization's sensitive data. In our demonstration, we used partially homomorphic cryptosystem in our protocols and showed practicality and feasibility of our proposed solution.
Open Access
Dynamic attribute-based privacy-preserving genomic susceptibility testing
(Association for Computing Machinery, 2019) Namazi, M.; Ayday, Erman; Eryonucu, Cihan; Perez-Gonzalez, F.
Developments in the field of genomic studies have resulted in the current high availability of genomic data which, in turn, raises significant privacy concerns. As DNA information is unique and correlated among family members, it cannot be regarded just as a matter of individual privacy concern. Due to the need for privacy-enhancing methods to protect these sensitive pieces of information, cryptographic solutions are deployed and enabled scientists to work on encrypted genomic data. In this paper, we develop an attribute-based privacy-preserving susceptibility testing method in which genomic data of patients is outsourced to an untrustworthy platform. We determine the challenges for the computations required to process the outsourced data and access control simultaneously within patient-doctor interactions. We obtain a non-interactive scheme regarding the contribution of the patient which improves the safety of the user data. Moreover, we exceed the computation performance of the susceptibility testing over the encrypted genomic data while we manage attributes and embedded access policies. Also, we guarantee to protect the privacy of individuals in our proposed scheme.
Open Access
Privacy-preserving protocols for aggregate location queries via homomorphic encryption and multiparty computation
(2019-07) Eryonucu, Cihan
Two main goals of the businesses are to serve their customers better and in the meantime, increase their pro t. One of the ways that businesses can improve their services is using location information of their customers (e.g., positioning their facilities with an objective to minimize the average distance of their customers to their closest facilities). However, without the customer's location data, it is impossible for businesses to achieve such goals. Luckily, in today's world, large amounts of location data is collected by service providers such as telecommunication operators or mobile apps such as Swarm. Service providers are willing to share their data with businesses, doing this will violate the privacy of their customers. Here, we propose two new privacy-preserving schemes for businesses to utilize location data of their customers that is collected by location-based service providers (LBSPs). We utilize lattice based homomorphic encryption and multiparty computation for our new schemes and then we compare them with our existing scheme which is based on partial homomorphic encryption. In our protocols, we hide customer lists of businesses from LBSPs, locations of the customers from the businesses, and query result from LBSPs. In such a setting, we let the businesses send location-based queries to the LBSPs. In addition, we make the query result only available to the businesses and hide them from the LBSPs. We evaluate our proposed schemes to show that they are practical. We then compare our three protocols, discussing each one's advantages and disadvantages and give use cases for all protocols. Our proposed schemes allow data sharing in a private manner and create the foundation for the future complex queries.