Private Proximity Testing with an Untrusted Server

摘要

The privacy of location-based services has gained attention with their increased popularity. To date, citing insufficient privacy demand and inefficient/immature privacy preserving technologies, service providers have not been willing to build private-enhanced systems in which they do not have access to users' location information. However, current practice is likely to change in coming years with increasing privacy awareness and technological advances. For instance, Narayanan et al. recently introduced a fast private equality testing protocol for proximity testing with an untrusted server. In the current work, based on basic notions of geometry and linear algebra, we describe a new three-party protocol for solving the same problem. Our proposed protocol decreases the number of encryptions needed and gives a more efficient solution for private equivalence testing.