Any cloud is a secure backup on Linux if you use rclone crypt :)

It works with Google Drive, Dropbox, One Drive, and countless others to create an encrypted cloud storage, where the cloud provider can never view your file contents.

I've loved using Backblaze B2 buckets. Been using them for years and it's very reasonable. Many different backup titles can use them.

Maybe consider a Hetzner storage box. They support borg, restic, rsync and probably more, there's no ingress or egress fees and you get unlimited traffic. Very nice for off-site backups if, like myself, you're on a limited budget.

You can try rclone, but their Proton Drive integration is in beta
https://rclone.org/protondrive/

I use rclone and duplicati depending on the needs of the backup.

For long term I use duplicati, it has a GUI and you can upload it to several places (mines are spread between e2 and drive).
You configure the backend, password for encryption, schedule, and version retention.

rclone, with the crypt submodule, you use it to mount your backups as am external drive, so you need to manually handle the actual copy of the data into it, plus versioning and retention.

So there’s a storage protocol called “S3” (I wanna say it stands for simple scalable storage?), first created by Amazon for AWS. Many types of software, including backup programs, have been designed to use it as a storage backend. There are now many S3 compatible providers, last I looked the best value was backblaze B2.

You need a backup program with end-to-end encryption, S3 compatibility, and whatever other features you like. I use restic but it’s CLI only, there’s also borg backup and many others.

If you encrypt locally with a good key, you don’t have to trust the remote storage provider. They just see a bunch of meaningless noise. Just don’t lose the key or your backup is useless.

Duplicati or BackRest and use any S3 compatible storage such as Backblaze B2, iDrive E2, Wasabi S3, etc..

If you make a backup with a tool like Borg that creates encrypted archives, then using AWS S3 glacier is the cheapest.

What's bad about it: if you ever need those files again, it's going to be VERY expensive to download them again, so it has to be treated as the "what if a nuke hits my city and all the local and off-site backups are vaporized" solution

Also: it's not recommended to directly host plain files, they need to be in an archive format with big chunks, as the API calls that are used to list them during sync are counted in a very expensive way

Cryptomator encrypts voulumes you can store/sync anywhere.

I use rsync.net, it's not as cheap as some, but I like the simplicity of storage I can access with rsync, rclone, sshfs etc.

You can run some commands remotely too, so I used rclone to copy my OneDrive files directly from the cloud files to rsync.net. Not through my PC.

I personally use restic for local backups which then get synced with rclone into a Hetzner Storage Box.

Run a transparent encryption program and buy a Google drive subscription of 2TB for a year for $100.

R2 has no ingress or egress fees