Quantum-secure protocols for privacy preserving location based services

Location Based Service (LBS) uses users’ geographic location to provide relevant and personalized services. However, privacy concerns arise for both users and service providers. Users wish to receive necessary information based on location-related queries without revealing the content of their queries to preserve privacy. At the same time, the location server must protect its valuable data from unauthorized access, as this data is a critical asset. In this manuscript, we address this problem and provide a solution to it by utilizing an oblivious transfer (OT) protocol. We propose a $k$-out-of-$n$ quantum oblivious transfer protocol (namely GqOT) as a solution to the above-mentioned problem. We describe the problem and the application of our proposed GqOT to solve the privacy preserving issues of users and service providers during LBS. The solution is practical and efficient as the source of quantum states for GqOT is single photons. Consequently, simple projective measurements are required to measure the quantum states. Moreover, GqOT also provides long-term security, ensuring a significant solution to the problem LBS addresses.