> For the complete documentation index, see [llms.txt](https://docs.hiveauth.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.hiveauth.com/developer-documentation/has-for-applications/challenge/challenge-refusal.md).

# Challenge refusal

If the user doesn't approve the challenge request, the **PKSA** will send a refusal message to the **HAS**. The **HAS** will then forward the following message to the **APP**:

### challenge\_nack

```
{
    cmd: "challenge_nack",
    uuid: string,
    data: string
}
```

{% tabs %}
{% tab title="Properties" %}

* **`uuid`**: the challenge request identifier
* **`data`**: the `uuid` encrypted with `auth_key` and converted to Base64
  {% endtab %}
  {% endtabs %}