|`backup`|`object`|<table> <tr> <td>Field </td><td>Type </td><td> </td></tr><tr> <td><code>algorithm</code></td><td>required <code>string</code></td><td>One of the algorithms listed at <ahref="https://spec.matrix.org/v1.9/client-server-api/#server-side-key-backups">https://spec.matrix.org/v1.9/client-server-api/#server-side-key-backups</a></td></tr><tr> <td><code>key</code></td><td>required <code>string</code></td><td>TODO </td></tr><tr> <td><code>backup_version</code></td><td>required <code>string</code></td><td>TODO </td></tr></table>|
|`backup`|`object`|<table> <tr> <td>Field </td><td>Type </td><td> </td></tr><tr> <td><code>algorithm</code></td><td>required <code>string</code></td><td>One of the algorithms listed at <ahref="https://spec.matrix.org/v1.9/client-server-api/#server-side-key-backups">https://spec.matrix.org/v1.9/client-server-api/#server-side-key-backups</a></td></tr><tr> <td><code>key</code></td><td>required <code>string</code></td><td>Unpadded base64 encoded private/secret key</td></tr><tr> <td><code>backup_version</code></td><td>required <code>string</code></td><td>The backup version as returned by [`POST /_matrix/client/v3/room_keys/version`](https://spec.matrix.org/v1.10/client-server-api/#post_matrixclientv3room_keysversion)</td></tr></table>|