Atempo does in fact support encryption of backup data in the following modes:

• In-flight (Over the wire as data is transferred over the network) 
• At Rest (Data is saved to backup media for long-term storage)

However, data is by default NOT excrypted as it makes the backup storage less efficient.  So, only customers with PCI Compliance status are generally enabled for encryption while all other customer data is sent as plain text unless it has been previously encrypted by another process or procedure.