The Relational Database Service now supports Backup Encryption. For all existing MySQL and PostgreSQL instances that have been created with Disk Encryption (as shown in the image below), an encrypted backup is now created for any type of manual or automatic backup task. With the automatic backup, nothing has to be done at this point, the encryption takes in place automatically.
To use this functionality, an instance must be created with Disk Encryption or an existing instance was created with Disk Encryption selected.
Subsequent activation of Disk Encryption after creation of a MySQL or PostgreSQL database is not possible. Find more information here.
Further information can be found in the RDS area of the Help Center.