{
    "heads": [
        {
            "instance": "SA-PHY-000003",
            "size": 0,
            "hash": "0000000000000000000000000000000000000000000000000000000000000000",
            "chain_ok": true,
            "signed": "BrainSAIT-AI-PROVENANCE-v1\nSA-PHY-000003\n0\n0000000000000000000000000000000000000000000000000000000000000000\n2026-11-08T18:10:41Z",
            "kid": "did:web:registry.brainsait.de#key-1",
            "sig": "K8ywD_EVGaba69XhsdJ2yI5U42-ndBlHE2pDarv5p8W89X37srf15XGaMjpU3XNpkgR0f_Tx7jgGJaV-t1kZAA"
        }
    ],
    "genesis": "0000000000000000000000000000000000000000000000000000000000000000",
    "did": "https://registry.brainsait.de/.well-known/did.json",
    "rule": "Each EMR keeps a hash chain of AI-assisted notes saved by clinicians: hash = sha256(line), line.prev = previous hash. The signature covers \"BrainSAIT-AI-PROVENANCE-v1\\ninstance\\nsize\\nhash\\ntime\" (Ed25519, key in the DID document)."
}