Which solution will meet these requirements?
Modify the DB instance to update the encryption key. Perform this update immediately without waiting for the next scheduled maintenance window.
Export the database to an Amazon S3 bucket. Import the data to an existing DB instance by using the export file. Specify a new encryption key during the import process.
Create a manual snapshot of the DB instance. Create an encrypted copy of the snapshot by using a new encryption key. Create a new DB instance from the encrypted snapshot.
Create a manual snapshot of the DB instance. Restore the snapshot to a new DB instance. Specify a new encryption key during the restoration process.
Explanations:
Amazon RDS does not support directly modifying the encryption key of an existing DB instance. The encryption key cannot be updated immediately on an active DB instance without replacing it.
Exporting the database to Amazon S3 and re-importing it is not a straightforward solution for replacing the encryption key. Additionally, specifying a new encryption key during the import process is not an option for RDS databases directly.
Creating a manual snapshot and then creating an encrypted copy of the snapshot using a new encryption key is the proper way to replace the encryption key. This method ensures that the new DB instance is encrypted with the new key.
Although restoring a snapshot to a new DB instance is possible, the encryption key cannot be changed during the restoration process. A new encryption key is only applied when creating an encrypted copy of the snapshot.
I estimate that the answer is:
Create a manual snapshot of the DB instance. Create an encrypted copy of the snapshot by using a new encryption key. Create a new DB instance from the encrypted snapshot.