Cloud file encryption?

Question

Backup

Good afternoon! Files are backed up on the local computer using rsnapshot. Then they must be uploaded to a remote server / cloud, how can the files be protected and encrypted without creating an extra copy.
Let's allow the option of auto-encryption immediately on the local computer (in the target directory)
Or you can offer the option of implementing a backup not with a snapshot, but with creating archives of 200 MB, but the following system for creating archives must be observed:
1. Once every four weeks, a full backup
2. Every week backup differential from full
3. Daily backups every day.
In this case, each weekly replaces the previous, daily daily, and full - full.

Answer 1

I understand that if you have rsnapshot, then this is linux.
Then you have a direct road to ecryptfs manuals. For example, here (however, it seems to be under win / macos as well).
In this case, of course, you need to synchronize to the cloud the directory in which the encrypted files are stored, and not the one in which you mount the decrypted crypt.
Unlike encrypted containers, in this case, a separate modified file will correctly go to the cloud.