Blockchain Healthcare AI Proof Receipts
AI models trained on clinical data need auditable provenance. Blockchain provides it.
When a hospital allows an AI company to train a model on its clinical data, several questions arise: What data was used? When did training occur? Was raw PHI exported? Can the training be independently verified? These questions matter to regulators, to hospital governance boards, to patients, and to downstream users of the trained model.
Rapha Protocol answers these questions by anchoring cryptographic proof receipts on Polygon mainnet. The blockchain serves as an immutable, public audit trail — without ever containing clinical data itself.
What goes on-chain — and what doesn't
Published on Polygon mainnet:
- Proof anchor transaction hash.
- Job ID and node token ID.
- Data hash (SHA-256 of output).
- Edge node SHA-256 (hardware identity).
- AI developer wallet address.
- Settlement amounts (USDC) and split percentages.
- Block timestamp (proof of timing).
- Zero-raw-PHI-export field (boolean).
- Contract event log (ProofAnchored, ProofSettled).
Never published anywhere:
- Raw patient data (DICOM pixels, FHIR bundles, EHR rows).
- Patient identifiers or PHI.
- Training data content (clinical notes, lab values, imaging).
- Model architecture details (proprietary IP).
- Intermediate training states or gradients.
- Private keys or attestation secrets.
Current mainnet proof surface
Network: Polygon Mainnet (Chain ID 137)
Proof anchor contract: 0xB27704CA8A01Bc151181D1d53E2F0eF11B39B32F
Proof anchor transaction: 0xfadab8cc5e6bdb531d7ddfd64fd2a325a5dabda1c0f1eb7a21f05d15c618f9a0
Block: 86473343
Edge node SHA-256: d0e387c30a53affa5b55afd83699086f43f7d0403ae5046aa0dac6d1eb81c5cd
Settlement contracts: RaphaNodeNFT (0x19432C08a4806f961D0ec589c6B68fe258E34d07), RaphaClearingVault (0x952F6d72fA210C73A9e1A9bf171B27488cF6Aa3C)
Why Polygon and not Ethereum mainnet?
Polygon (formerly Matic) is an Ethereum Layer 2 scaling solution providing:
- Low transaction costs: Proof anchoring on Ethereum mainnet can cost $50-500+ per transaction. Polygon transactions cost fractions of a cent — making per-job proof anchoring economically viable.
- EVM compatibility: Smart contracts are written in Solidity and deploy identically to Ethereum and Polygon. The RaphaClearingVault and RaphaNodeNFT contracts use standard OpenZeppelin libraries.
- USDC native: Native USDC on Polygon (0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359) provides the settlement currency without bridging overhead.
- Ecosystem maturity: Polygon hosts thousands of dApps and has $1B+ in total value locked. It is the most deployed-on Layer 2 for institutional DeSci and enterprise blockchain applications.
Important: A mainnet proof receipt proves a cryptographic commitment and transaction inclusion. It does not prove clinical validity, regulatory approval, model safety, de-identification, or HIPAA/GDPR/Taiwan PDPA compliance. The receipt is an audit tool — not a regulatory certification.