Traditional Lending Problem
🤖 Bot farms create 1,000+ fake accounts
A single bad actor can drain an entire lending protocol by creating fake identities and requesting multiple loans.
💸 $2.3B lost to sybil attacks in 2024
Traditional KYC costs $50/user and can still be gamed with stolen or fake IDs.
📍 Remote verification isn't enough
Digital identity (passport scans, selfies) can be faked or compromised. You need proof of physical presence.
Our Proximity Solution
📍 Physical co-location required
Borrower and merchant must be within 10 meters (BLE range) to request a loan. Bot farms can't fake physical proximity.
🔐 Cryptographic proof on-chain
Both parties sign the proximity proof with their private keys. The blockchain validates signatures and distance.
💰 Dramatically lower fraud rates
Requiring physical presence makes it economically unfeasible for bot farms to attack the system at scale.
See BLE Proximity in Action
Watch our Solana Hackathon 2025 demo showing real-time proximity verification
🎯 The Problem
Bot farms can create 1,000+ fake accounts and drain lending protocols in under an hour. GPS, QR codes, and video calls all fail because they can be spoofed remotely.
✅ Our Solution
BLE proximity verification with Ed25519 cryptographic signatures and RSSI signal strength validation. Physical radio proximity can't be faked - you must be within 10 meters.
📊 Proven Traction
- ✓Already live on World Chain Mainnet
- ✓3 merchants in Philippines
- ✓85% repayment rate
- ✓$12,000+ loans disbursed
🚀 Built on Solana
- →Complete Anchor smart contract
- →BLE proximity protocol with replay attack prevention
- →100x cheaper transactions ($0.002 vs $0.20)
How BLE Proximity Verification Works
A simple, elegant solution that makes fraud prohibitively expensive
1. Merchant Broadcasts
Store broadcasts BLE beacon with encrypted merchant ID
2. Customer Detects
Customer app scans and measures signal strength (RSSI)
3. Both Sign Proof
Merchant & customer cryptographically sign proximity data
4. Blockchain Verifies
Smart contract validates signatures and proximity on-chain
What Gets Verified On-Chain:
📡 Signal Strength (RSSI)
-55 to -80 dBm ≈ within 10 meters. Too weak = too far away, rejected.
🔐 Dual Signatures
Both merchant and customer must sign. Can't fake either party.
⏱️ Timestamp Freshness
Proof must be <5 minutes old. Prevents replay attacks.
struct ProximityProof {
merchant_pubkey: PublicKey,
customer_pubkey: PublicKey,
rssi: i8, // -65 dBm = ~5 meters
timestamp: i64, // Unix timestamp
nonce: [u8; 32], // Random nonce
merchant_signature: [u8; 64],
customer_signature: [u8; 64]
}
// On-chain verification
fn verify_proximity(proof: ProximityProof) {
✓ Check RSSI is within range (-55 to -80 dBm)
✓ Check timestamp is recent (< 5 minutes old)
✓ Verify merchant signature is valid
✓ Verify customer signature is valid
✓ Both signatures match the same message
}Why Physical Proximity Matters
Bot Farms Can't Scale
A bot farm in Bangladesh can't physically visit 1,000 stores in the Philippines. Physical presence requirement makes attacks economically unfeasible.
Instant, Costless Verification
No $50 KYC fees, no waiting for ID verification. BLE detection happens in seconds, automatically, at zero cost.
Merchant Trust Network
Merchants know their customers. Requiring physical presence leverages local community trust instead of distant algorithms.
Real-World Impact: The Numbers
🌐 Blockchain-Agnostic Technology
Our BLE proximity verification works on any blockchain that supports smart contracts. We've built it on World Chain (Ethereum L2) and Solana, but the concept applies universally.
✅ World Chain (Ethereum L2)
Currently live with 3 merchants, $12K+ disbursed. Integrates with World ID for additional sybil resistance.
⚡ Solana
Built for Solana Hackathon 2025. Faster transactions (65K TPS), lower costs ($0.0001 per tx).
🔮 Any Smart Contract Chain
The verification logic can be deployed on Polygon, Arbitrum, Base, or any chain with smart contracts.
💡 The Innovation: Physical proximity as fraud prevention is the breakthrough - the blockchain is just the settlement layer.
Future Enhancements
We're constantly improving the technology based on real-world testing and security research
🔧 V1 (Current): BLE with Dual Signatures
- ✓Bluetooth Low Energy (BLE) for proximity detection
- ✓Dual signatures (merchant + customer) prevent spoofing
- ✓RSSI validation (-55 to -80 dBm range check)
- ✓Timestamp freshness (<5 minute window)
🚀 V2 (Future): Ultra-Wide Band (UWB)
- →UWB time-of-flight for precise distance measurement
- →Resistant to relay attacks (NCC Group research recommendation)
- →Sub-meter accuracy vs BLE's ~5 meter accuracy
- →Newer phones support (iPhone 11+, Samsung S21+)
Migration planned for Q2 2025 as UWB adoption grows
Security Research: We actively monitor security research (like NCC Group's BLE relay attack findings) and adapt our approach accordingly. Our dual-signature design mitigates many relay attack vectors.