{
  "title": "FutoIn 'sec' field - HMAC",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "ksn",
    "hmac"
  ],
  "properties": {
    "ki": {
      "type": "string",
      "description": "Base shared secret ID"
    },
    "di": {
      "type": "string",
      "description": "Derived key sequence ID"
    },
    "hmac": {
      "type": "string",
      "description": "Base64 encoded HMAC"
    }
  }
}