{
  "version": "EC_v1",
  "data": "encodedPaymentData",
  "signature": "signatureBytes",
  "header": {
    "ephemeralPublicKey": "MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE...",
    "publicKeyHash": "hash==",
    "transactionId": "abc123transaction"
  }
}