json_schema: {
      "properties": {
          "cipher": {
              "enum": [
                  "aes-128-ctr"
              ],
              "type": "string"
          },
          "cipherparams": {
              "additionalProperties": false,
              "properties": {
                  "iv": {
                      "pattern": "^([0-9]|[a-f]){32}$",
                      "type": "string"
                  }
              },
              "required": [
                  "iv"
              ],
              "type": "object"
          },
          "ciphertext": {
              "pattern": "^(([0-9]|[a-f]){2}){0,32}$",
              "type": "string"
          }
      },
      "required": [
          "cipher",
          "cipherparams",
          "ciphertext"
      ],
      "type": "object"
  }