# Authentication approval

If the user approves the authentication request, the **PKSA** must:

* create a new `token` with an `expire` value or reuse an existing one.
* store the `token`, `expire` and `key` values locally.
* create an "authentication approval data" object (`auth_ack_data`) that it will send to the **APP**

The structure of the `auth_ack_data` is:

### auth\_ack\_data

```js
{
    token: string, // protocol < 1.0 only
    expire: number,
    challenge: object = undefined
}
```

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

* **`token`**: session token (we recommend using a UUID) - ***Deprecated since protocol v1.0***
* **`expire`**: UNIX timestamp when the authentication will expire
* **`challenge`**: *optional* if the **APP** provided a `challenge_data` object with its `auth_req_data`, the **PKSA** must return a `challenge_ack_data` object (see [Challenge approval](/has-for-wallets-pksa/challenge/challenge-approval.md) ).
  {% endtab %}
  {% endtabs %}

The **PKSA** must then encrypt the `auth_ack_data` object using the encryption key previously shared with the **APP** (`auth_key`).

Finally, the **PKSA** then inform the **HAS** of the user's approval by sending the following message:

### auth\_ack

```javascript
{
    cmd: "auth_ack",
    uuid: string,
    data: string,
    pok: string
}
```

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

* **`uuid`**: the request identifier
* **`data`**: `auth_ack_data` encrypted with the `auth_key` and converted to Base64
* **`pok`**: the `uuid` encrypted using the account private key and the HAS server public key (see [Proof of Key](/has-for-wallets-pksa/proof-of-key.md))
  {% endtab %}
  {% endtabs %}

> The encryption of `auth_ack_data` is performed to ensure that a malicious actor operating a **HAS** cannot bypass the **PKSA** to approve an authentication request.
>
> It will also make the **HAS** unaware of what's going on between the app and the PKSA and unable to tamper with the authentication request process.
>
> Being the only one being able to decrypt the `auth_ack.challenge` using its encryption `auth_key`, the **APP** has 100% certainty that the encryption process was made by a **PKSA** which got the encryption `auth_key` from reading the off-band `auth_req_payload`.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.hiveauth.com/has-for-wallets-pksa/authentication/authentication-approval.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.