I have a synology NAS where I backup my photos to. What would be the most cost effective way to encrypt and back up this data without having to purchase another NAS and install it at a family member’s house. It would be about 5 TB and would not touch the data unless my NAS completely takes a crap.
My go-to backup strategy is USB hard drives. They’re cheap, they’re fast, and nobody’s going to even try to decrypt them. Buy several, put them in a safety deposit box at your bank, rotate them weekly, and nothing short of a nuclear weapon will destroy every copy of your data at the same time.