LocProof

Tamper-proof digital witness. Cryptographic evidence that two parties were physically present at the same location. Court-admissible, blockchain-anchored, impossible to fake.

Use Cases

• Logistics — chain-of-custody handoffs between drivers, warehouses, recipients.
• Insurance — verify claimant presence at incident location.
• Legal — witness/notary/contract-signing presence attestation.

How It Works

1. Your server requests a proof via the LocProof API; we return a single-use nonce.
2. Two devices, each running the LocProof SDK, collect signals (GPS, WiFi, BLE, barometer) and sign their observations with their Ed25519 device keys.
3. LocProof correlates the observations, computes a proximity score, and returns a signed ProximityProof that your system (or a counterparty) can verify offline.

Pricing

Per-proof, Twilio-style. Volume discounts.

Running Locally

LocProof has two key types:

• Bootstrap admin key (lp_admin_<32 hex>) — set via LOCPROOF_API_KEY. Gates /admin/* only. Used to mint and manage customers.
• Customer keys (lp_live_<32 hex>) — minted via POST /admin/customers, stored as SHA-256 hashes. Gate /v1/*. The plaintext is returned exactly once at creation.

/health is public.

# 1. Set the bootstrap admin key and start the server.
export LOCPROOF_API_KEY="lp_admin_$(openssl rand -hex 16)"
cargo run -p locproof-api

# 2. Mint a customer key.
curl -sX POST http://localhost:3000/admin/customers \
  -H "X-API-Key: $LOCPROOF_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name":"acme"}'
# → {"id":"…","name":"acme","api_key":"lp_live_…","created_at":"…"}

# 3. Use the returned customer key on /v1/*.
curl -X POST http://localhost:3000/v1/proofs \
  -H "X-API-Key: lp_live_…" -d @proof.json

If LOCPROOF_API_KEY is unset, the server requires LOCPROOF_DEV=1 and starts with /admin/* open (no admin auth). /v1/* always enforces a real customer key — mint one via the open /admin/customers in dev. Don't ship dev mode.

The server signing keypair is persisted at data/server.key (mode 0600, gitignored). Delete it and restart to rotate.

Roadmap

Phase 1 (Current) — API Foundation

• Core proof types + scoring ✓
• PostgreSQL storage ✓
• API auth + rate limiting ✓
• Customer management (in progress)

Phase 2 — Mobile SDKs

• iOS SDK (Swift)
• Android SDK (Kotlin)
• Signal collection (BLE, GPS, Barometer)

Phase 3 — Blockchain Anchoring

• Anchor proof hashes to Base L2
• EIP-712 typed signatures
• Batch anchoring with Merkle trees
• On-chain verification contract

Phase 4 — Dashboard + Billing

• Next.js customer dashboard
• Stripe billing integration
• Usage analytics

Phase 5 — Production Launch

• Akamai/Vultr deployment
• Monitoring + alerting
• Documentation site

Status

Early development. Protocol spec in docs/PROTOCOL.md.

License

BUSL 1.1. Source-available; commercial production use requires a license from ChronoCoders.