# Step 2: Identify the keys

Each device has a unique combination of security keys that are used by the LNS to identify the device and provide access to the data being sent via LoRa. TWTG will send these keys in an encrypted file alongside the shipment confirmation after purchase. 

The file will contain the following information:

* Serial Number 
* devEUI
* appEUI/joinEUI
* appKey

{% hint style="info" %}
From LoRaWAN 1.0.4 appEUI is known as joinEUI
{% endhint %}

The devEUI and the appKey will be requested by the LNS when adding a device. The appEUI/joinEUI is only needed for end-to-end encryption between the device and the application server, and therefore should not be entered in the LNS but in the application server. This is not mandatory, therefore in many situations, the appEUI/joinEUI is not needed at all. It is only needed when LNS and join server are separated and the application server does not trust the LNS.

{% hint style="info" %}
Please note that for security reasons TWTG will avoid sending the keys more than once. It is recommended that the user store these keys in a safe and documented location.
{% endhint %}

#### Examples of the key file

<table><thead><tr><th width="196">Transmitter ser. no.</th><th width="127">type</th><th>devEUI</th><th>appEUI/joinEUI</th><th>appKey</th></tr></thead><tbody><tr><td>TT0123AA00001</td><td>DS-TT-01-01</td><td>848BCD612345678</td><td>848BCDFFFEEEFFAB</td><td>7A4DFAA5F47A5C3A53FB349670D5B2AF</td></tr><tr><td>TT0123AA00002</td><td>DS-TT-01-01</td><td>848BCD600000000</td><td>848BCDFFFEEEFFAC</td><td>7A4DFAA5F47A5C3A53FB349670D5B2AE</td></tr></tbody></table>


---

# 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.twtg.io/docs/installation-and-provisioning/provisioning/step-2-identify-the-keys.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.