Private coordinates in a public world - ZK-location SDK

[Sixela33]

ZK-location

Summary

ZK-Location is a privacy-preserving primitive that enables users to prove their physical location within specific geographic regions without revealing their exact coordinates. This technology combines GNSS data, hierarchical geospatial indexing (H3), distance approximation algorithms, and cryptographic techniques to create a robust SDK for privacy-first location verification. The primitive is currently being used in ZK-Drop for regional airdrops and token presales, demonstrating its practical application in blockchain-based location verification.

• Demo: https://zk-drop-navy.vercel.app/
• Github: https://github.com/fabian416/ZK-Drop

Motivation

Location-based applications in crypto face several problems:

- Privacy risks: Users must reveal exact GPS coordinates to prove eligibility.
- Spoofing vulnerabilities: GPS spoofing and VPNs can be used to cheat regional restrictions.
- Exclusion: Users in underserved areas are often excluded from airdrops and presales.
- Compliance complexity: Projects struggle to meet geographic legal constraints while maintaining decentralization.

ZK-Location addresses these issues with a novel combination of hierarchical geospatial anonymization and zk-proof-based verification, enabling:

• Location proofs without disclosing coordinates
• Cryptographic spoof resistance via raw GNSS data
• Compliant and fair access to blockchain-based services

Business Model

Open source sdk for the community

Methodology

The ZK-Location primitive consists of several key components:

1. Core Components:

• GNSS Integration (Native)
  • Leverages native modules for high-fidelity raw GNSS data
  • Converts coordinates to secure processing format
• H3 Spatial Indexing
  • Converts geolocation to H3 cells for spatial anonymization
  • Enables efficient region-based inclusion proofs
• Secure Distance Computation
  • Uses Haversine formula with ElGamal encryption
  • Optional FHE integration via Zama's tools
• ZK Intersection and Bounding Box Inclusion
  • Proves location within predefined regions
  • Uses Noir circuits with Poseidon hash commitments

2. Architecture:

User Device:

• GNSS module
• ZK-Location SDK
  • GNSS parser
  • Coordinate scaler
  • H3 converter
  • ZK input preprocessor
  • ElGamal encryptor
  • Noir prover
    Backend / Verifier:
• Noir verifier (Solidity / Typescript)
• Smart contract for verification (EVM / zkRollup)

Timeline and Deliverables

Phase 1 (Weeks 1–5):

• Core SDK development
  • GNSS integration
  • H3 spatial indexing
  • Basic ZK circuit implementation
• Initial security audit
• Basic documentation

Phase 2 (Weeks 5–12):

• Advanced features
  • ElGamal encryption integration
  • FHE module development
  • Multi-chain support
• Developer SDK and documentation
• Performance optimization

Phase 3(Weeks 12–19)

• Enterprise features
  • Advanced analytics
  • Custom region support
  • Production deployment
• Security hardening
• Production documentation

Team:

Fabian Diaz
[email protected]

Alexis Jankowski
[email protected]

Sebastian Lujan
[email protected]

Luciano Carreno
[email protected]

• Contact email: [email protected]

Start Date

1 June

Questions

1. What are the specific security requirements for the circuit implementation?
2. Are there any regulatory compliance requirements for specific regions?
3. What is the expected scale of concurrent users?
4. Are there specific blockchain networks that need to be supported?
5. What are the performance requirements for proof generation and verification?
6. How should we handle the tradeoffs between ElGamal and FHE approaches?
7. What are the specific GNSS spoofing resistance requirements?
8. What is the target latency for on-device proof generation?

[TCMains]

It's nice to explore Github

[TCMains]

Github on Zama