The content is currently stored in plaintext on the disk by Garage, so you have to encrypt the data yourself. For example, you can configure your server to encrypt at rest the partition that contains your `data_dir` and your `meta_dir` or build/use applications that supports client-side encryption such as rclone with its crypt module[0] or Nextcloud with its end-to-end encryption module[1].
[0]: https://rclone.org/crypt/
[1]: https://nextcloud.com/endtoend/