# Aria: Encryption Keys

As with other storage engines that support data-at-rest encryption, Aria relies on an [Encryption Key Management](/docs/server/security/encryption/data-at-rest-encryption/key-management-and-encryption-plugins.md) plugin to handle its encryption keys. Where the support is available, Aria can use [multiple keys](/docs/server/security/encryption/data-at-rest-encryption/key-management-and-encryption-plugins/encryption-key-management.md#using-multiple-encryption-keys).

## Encryption Keys

MariaDB keeps track of each encryption key internally using a 32-bit integer, which serves as the key identifier. Unlike [InnoDB](/docs/server/security/encryption/data-at-rest-encryption/innodb-encryption.md), Aria does not support the [ENCRYPTION\_KEY\_ID](/docs/server/server-usage/tables/create-table.md#encryption_key_id) table option (for more information, see [MDEV-18049](https://jira.mariadb.org/browse/MDEV-18049)), which allows the user to specify the encryption key to use. Instead, Aria defaults to specific encryption keys provided by the Encryption Key Management plugin.

* When working with user-created tables, Aria encrypts them to disk using the ID 1 key.
* When working with internal temporary tables written to disk, Aria encrypts them to disk using the ID 2 key, unless there is no ID 2 key, then it falls back on the ID 1 key.

## Key Rotation

Some [key management and encryption plugins](/docs/server/security/encryption/data-at-rest-encryption/key-management-and-encryption-plugins/encryption-key-management.md) allow you to automatically rotate and version your encryption keys. If a plugin support key rotation, and if it rotates the encryption keys, then InnoDB's [background encryption threads](/docs/server/security/encryption/data-at-rest-encryption/innodb-encryption/innodb-background-encryption-threads.md) can re-encrypt InnoDB pages that use the old key version with the new key version. However, Aria does **not** have a similar mechanism, which means that the tables remain encrypted with the older key version. For more information, see [MDEV-18971](https://jira.mariadb.org/browse/MDEV-18971).

In order for key rotation to work, both the backend key management service (KMS) and the corresponding [key management and encryption plugin](/docs/server/security/encryption/data-at-rest-encryption/key-management-and-encryption-plugins/encryption-key-management.md) have to support key rotation. See [Encryption Key Management: Support for Key Rotation in Encryption Plugins](/docs/server/security/encryption/data-at-rest-encryption/key-management-and-encryption-plugins/encryption-key-management.md#support-for-key-rotation-in-encryption-plugins) to determine which plugins currently support key rotation.

<sub>*This page is licensed: CC BY-SA / Gnu FDL*</sub>

{% @marketo/form formId="4316" %}


---

# 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://mariadb.com/docs/server/security/encryption/data-at-rest-encryption/aria-encryption/aria-encryption-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.