Restic's rest-server does this too, or afaik you can configure restic to use S3 with object locks or whatever it's called Edit: just saw your sibling / reply-t

Restic's rest-server does this too, or afaik you can configure restic to use S3 with object locks or whatever it's called Edit: just saw your sibling / reply-to-self comment. This setup would fulfill the requirements you posted, or at least I would assume that restic runs under (or compiles for) your nix OS. It doesn't use asymmetric encryption for this but the goal of append-only is there > because the snapshots are encrypted, it is impossible for the rsync.net storage to see or even know that large parts of the encrypted data is identical If they don't see a large amount of data incoming, they'll know large parts of the data are identical (or removed, I suppose). Hiding traffic volumes is fundamentally only possible by introducing dummy data