> For the complete documentation index, see [llms.txt](https://developer.magtek.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.magtek.com/api-and-command-reference/dynafamily-programmers-manual/commands/0xennn-security/0xef01-load-key-using-tr-31.md).

# 0xEF01 - Load Key Using TR-31

The host uses this command to load a key into one of several available slots in the device’s secure memory.

## Device Key ID / Slot

| ID   | Label     | Description                       | Load TK |
| ---- | --------- | --------------------------------- | ------- |
| 1000 | TMPTK     | Temporary KBPK                    | agree   |
| 1001 | MTK       | Master Transport                  | TMPTK   |
| 1002 | DEVTK     | Device Master                     | MTK     |
| 1003 | FINTK     | Financial Master                  | MTK     |
| 1021 | PRODTK    | Production - MagTek Internal Only | DEVTK   |
| 1022 | MFGTK     | MagTek Only Internal/External     | DEVTK   |
| 1081 | MKIFTK    | MagTek KIF Financial Keys         | FINTK   |
| 1101 | FREQMK    | Factory Request MAC               | PRODTK  |
| 1102 | MREQMK    | Mfg Device Request MAC            | MFGTK   |
| 1111 | MFRQMK    | Mfg Financial Request MAC         | MKIFTK  |
| 20xx | DKPTM0-1F | MagTek DUKPT Initial Key          | MKIFTK  |

To inject a specific key in the above table, the corresponding Load TK shall be injected previously.

As shown in the table, MTK injection requires that a TMPTK has been created. See [<mark style="color:red;">**Command 0xF017 - Establish Ephemeral KBPK**</mark>](https://developer.magtek.com/api-and-command-reference/dynafamily-programmers-manual/commands/0xfnnn-manufacturing/0xf017-establish-ephemeral-kbpk).

After MTK has been injected successfully, the sequence of injecting other keys is as follows:

{% stepper %}
{% step %}

### Establish a secure session (Get Challenge)

The host uses [<mark style="color:red;">**Command 0xE001 - Get Challenge**</mark>](https://developer.magtek.com/api-and-command-reference/dynafamily-programmers-manual/commands/0xennn-security/0xe001-get-challenge) to establish a secure session with the device.
{% endstep %}

{% step %}

### Construct TR-31 key block

The host constructs a TR-31 (X9.143) key block for the key it is going to load. (Note that the Load Key must be injected previously.)
{% endstep %}

{% step %}

### Construct command request

The host constructs the command request for [<mark style="color:red;">**Command 0xEF01 - Load Key Using TR-31**</mark>](https://developer.magtek.com/api-and-command-reference/dynafamily-programmers-manual/commands/0xennn-security/0xef01-load-key-using-tr-31) in the format below.
{% endstep %}

{% step %}

### Send the command

The host sends the command request to the device.
{% endstep %}

{% step %}

### Device response

The device sends a response in the format below to the host.
{% endstep %}
{% endstepper %}

## Load Key Using TR-31 - Request Data for Command 0xEF01

<table><thead><tr><th>Tag</th><th width="76.33331298828125">Len</th><th width="243">Value / Description</th><th width="76">Typ</th><th width="77.6666259765625">Req</th><th width="98.6666259765625">Default</th></tr></thead><tbody><tr><td>Beginning of any wrappers, at minimum including <strong>Request Message</strong> </td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>EF01 = <strong>Load Key Using TR-31 - Command 0xEF01</strong> </td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>84</td><td>var</td><td>Key Block — This is a populated, secured <a href="https://developer.magtek.com/api-and-command-reference/dynafamily-programmers-manual/data-types-and-shared-tlv-data-objects/mifare-card-data-type-emv-contactless-only"><mark style="color:red;"><strong>MIFARE Card Data Type (EMV Contactless Only)</strong></mark> </a></td><td>B</td><td>R</td><td></td></tr><tr><td>DFDFDF40</td><td>var</td><td>MIFARE Card Data in ASCII terminated with NULL character</td><td></td><td></td><td></td></tr><tr><td>DFDFDF41</td><td>var</td><td>MIFARE Card Data in Binary (optional)</td><td></td><td></td><td>O</td></tr><tr><td>TR-31 Key Block Type.</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>End of any wrappers, at minimum including <strong>Request Message</strong></td><td></td><td></td><td></td><td></td><td></td></tr></tbody></table>

## Load Key Using TR-31 - Response Data for Command 0xEF01

<table><thead><tr><th width="241">Tag</th><th width="75">Len</th><th>Value / Description</th><th width="73.66668701171875">Typ</th><th width="75.333251953125">Req</th><th width="98">Default</th></tr></thead><tbody><tr><td>Beginning of any wrappers, at minimum including <strong>Response Message</strong> </td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>EF01 = <strong>Load Key Using TR-31 - Command 0xEF01</strong> </td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>No parameters.</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>End of any wrappers, at minimum including <strong>Response Message</strong> </td><td></td><td></td><td></td><td></td><td></td></tr></tbody></table>

#### Request Example&#x20;

{% code title="Example (Hex)" %}

```
AA 00 81 04 01 1A EF 01 84 82 01 36 EF 01 84 82 01 30 44 30 33 30 34 42 31 54 58 30 30 
4E 30 36 30 30 49 4B 31 38 46 46 46 46 39 38 37 36 35 34 33 32 31 30 33 30 30 30 30 30 
32 31 35 38 4D 47 54 4B 31 30 30 31 54 31 31 30 34 32 30 30 37 31 32 30 34 31 30 38 31 
32 31 30 34 30 30 33 46 33 31 30 37 42 35 30 41 46 44 32 33 32 31 30 43 39 33 36 31 39 
44 44 41 41 32 31 33 36 43 37 33 33 31 30 32 30 32 30 31 32 30 34 54 31 37 31 36 33 30 
5A 4B 50 30 45 30 31 39 33 36 46 41 33 32 45 4B 43 30 41 30 30 34 35 30 30 54 53 31 34 
32 30 32 30 30 39 30 32 54 31 35 35 38 30 32 5A 50 42 30 34 35 37 32 31 37 46 33 34 37 
31 34 43 32 42 38 38 46 33 39 35 35 32 32 32 46 46 35 39 41 41 30 35 37 44 39 39 41 46 
38 32 41 37 35 37 32 46 39 33 38 46 38 33 38 42 43 36 35 45 45 35 34 46 39 34 37 46 35 
39 41 30 36 43 44 34 35 35 31 39 32 32 37 41 32 35 35 43 37 44 35 44 37 43 38 36 37 34 
35 30 33 46 41 43 36 46 41 37 31 33 32 43 38 46 41 39 39 36 42 34 45 42 36 41 41 31 31 
34 46 45
```

{% endcode %}

#### Response Example&#x20;

{% code title="Response Example (Hex)" %}

```
AA 00 81 04 82 1A EF 01 82 04 00 00 00 00
```

{% endcode %}


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