Researchers develop privacy-preserving method to verify location without revealing exact coordinates

A team of computer scientists from universities in Germany, Hong Kong, and the UK has proposed a novel method called Zero-Knowledge Location Privacy (ZKLP) that allows users to prove their location without revealing exact coordinates. The research was presented at the 2025 IEEE Symposium on Security and Privacy.

The Privacy Challenge of Location Data

• Location data from mobile devices is highly sensitive, potentially revealing personal information about where people live, work, and socialize
• Current solutions like Geo-Indistinguishability and VPriv have limitations, including reliance on third-party anonymization

How ZKLP Works

• Uses zk-SNARKs (Succinct Non-Interactive Argument of Knowledge) to prove location claims without revealing actual data
• Implements the Discrete Global Grid System (DGGS), dividing the world into hexagonal grids for flexible privacy granularity
• Overcomes computational challenges by optimizing floating-point arithmetic for IEEE 754 compliance

Key Advantages

• 15.9× fewer constraints for FP32 values compared to fixed-point baseline
• Can perform 470 privacy-preserving proximity tests per second
• Enables verification of location claims without interaction

Limitations and Future Applications

• Doesn't prevent location spoofing - only verifies data validity, not authenticity
• Potential integration with systems like Apple's "Find My" network for provenance
• Could enhance:
  • Photo authentication via C2PA
  • Machine learning applications
  • Proof-of-Personhood mechanisms

The research represents a significant step forward in balancing location-based service functionality with user privacy protections.