I need to do daily copy of large file tree over the public internet, and do that effectively. As far as I know, if I use rsyncd on receive part then sync is done quite effectively since during file tree compare part both sides (sender and receiver) can scan existing file trees locally. This way, I suppose to sync to rsyncd and that's fine, but the sending will be in plain text and I need to encrypt it since I use public Internet.
On the contrary, if I run sync like this: rsync -a /localtree user@host:/remotetree/
then all is done by the same (local) rsync, it uses ssh to login to remote system, scan its filesystem and do the sync. Then I get encryption on all phases but the remote tree scan is not that effective.
So, looks like rsyncd is for effectiveness and rsync (over ssh) is for secureness? Do I have an option to use rsyncd securely without need to setup (explicit) VPN between hosts?
Please advice, since syncing files seems to be wildly used around and I suppose just miss something on encryption part.