Location Proofs
Location proofs are digital artifacts that combine multiple independent pieces of evidence to support claims about where and when events occur. They serve as the verification layer for location attestations in the Astral ecosystem.
Core Concepts
A location stamp is a single piece of verifiable evidence (e.g., a GNSS reading, an IP lookup, or a signed affidavit). A location proof is what you get when multiple stamps are combined and verified together to create a higher-confidence claim.
Location proofs serve as the verification layer for location attestations. They:
- Combine multiple independent evidence sources to increase confidence
- Can be generated through various verification strategies
- Are attached to location attestations as part of the Location Protocol
- Make location fraud more difficult through multifactor verification
Evidence Strategies
The Location Protocol supports seven broad categories of location evidence:
- Machine Identifiers: Wi-Fi, Bluetooth, cell towers, IP addresses
- Network Measurements: GNSS, RTT latency, signal strength
- Sensor Data: IMU, camera, microphone, environmental sensors
- Delegated: Third-party services like ride logs, utility bills
- Social: Peer attestations and community validation
- Authority: Institutional records and certifications
- Legal: Formal documents like bills of lading
Relationship to Location Attestations
Location attestations are the primary data structure in the Location Protocol, while location proofs provide the evidence that makes these attestations trustworthy:
- Location attestation: "I was at coordinates 37.7749° N, 122.4194° W at 2:00pm"
- Location proof: Multiple pieces of evidence supporting that claim, such as GNSS data + Wi-Fi signals + device attestation
Research & Implementation
For detailed technical research on location proof strategies, signals, and implementation approaches, see the Location Proofs section.
The Location Protocol accommodates various proof strategies through the Location Proof Extensions framework.