Differential Backups with 256-bit AES encryption

I am new to Toucan, but quite impressed so far.

I want to create a simple Job that will create Differential Backups using minimal drive space, but with 256-bit AES encryption: Is this possible?

I hope to backup sensitive data to a RAID 5 NAS system.

EDIT:
Strange. I have just been playing with the Differential Backup feature. I created a number of text files. I created a number of Differential Backups (7z) whilst I edited the text files. They seemed to backup OK. But then when I tried to Restore them, nothing was written (no files, no folders).