Anything secret involves a master key. If you don't trust AWS, then you need to supply your own master key. But for most setup, IMO, you should just let AWS handle the key management, and you use role to decrypt. Rotation is a big deal though. For server, SSH key can be encrypted in KMS and we either completely replace the box, or we rotate one box at a time. For DB servers, it's important to choose a DB that can stream data to a new box with as little impact as possible (or allows replication). But these takes time to develop (I can't use container to host DB or critical applications because the network performance, at least a year ago).<p>BTW Mozilla's sops [1] is quite interesting. I've been testing this for a while now.<p>[1]: <a href="https://github.com/mozilla/sops" rel="nofollow">https://github.com/mozilla/sops</a>