# Function: deriveInboxKeyBytes()

```ts
function deriveInboxKeyBytes(contactKey, gen): Promise<Uint8Array<ArrayBufferLike>>;
```

Defined in: [packages/core/src/identity/contact-key.ts:80](https://github.com/leifriksheim/minca/blob/main/core/src/identity/contact-key.ts#L80)

An inbox key, which knocks are sealed to (spec 07 §1). Not the contact key,
whose public half is on every profile: an inbox key says nothing about whose it is.

## Parameters

| Parameter | Type | Description |
| ------ | ------ | ------ |
| `contactKey` | `Uint8Array` | The contact key's private scalar (`deriveContactKeyBytes`) |
| `gen` | `number` | - |

## Returns

`Promise`\<`Uint8Array`\<`ArrayBufferLike`\>\>