> ## Documentation Index
> Fetch the complete documentation index at: https://turnkey-0e7c1f5b-bc-add-sdk-typedoc.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# BuildAdditionalAssociatedData

# Function: buildAdditionalAssociatedData()

> **buildAdditionalAssociatedData**(`senderPubBuf`, `receiverPubBuf`): `Uint8Array`

Defined in: [crypto.ts:294](https://github.com/tkhq/sdk/blob/ee72856c3f450731d7501ab05001215768b71500/packages/crypto/src/crypto.ts#L294)

Create additional associated data (AAD) for AES-GCM decryption.

## Parameters

### senderPubBuf

`Uint8Array`

### receiverPubBuf

`Uint8Array`

## Returns

`Uint8Array`

* The resulting concatenation of sender and receiver pubkeys.