Is there any application, preferably for Windows, that can handle this for me? Synchronise files with a cloud system, but encrypting/decrypting them transparently as they are uploaded/downloaded.
It can apparently run via WSL. The main selling point is that it's made by colin percival[1], so if you really care about the security of your backups, you can't get any better.
Additionally, it's fairly reasonably priced. When s3 dropped their prices so that tarsnap became cheaper to run, he passed that on directly to customers[2]
[0] https://www.tarsnap.com/faq.html
[1] https://en.wikipedia.org/wiki/Colin_Percival
[2] http://www.daemonology.net/blog/2014-04-02-tarsnap-price-cut...
It’s like orders of magnitude more expensive than S3 and b2.
As others mention a lot of closed source tools offer local encryption, including Backblaze (although I believe they need your key in order to do restores, which might or might not defeat the purpose depending on your use case).
I was searching for something the could replace Backblaze on Linux for me, and Vorta+BorgBase was even better than that.
Encrypted and compressed by default, deduplicated, life-long (if desired) and diffable history, every snapshot can be mounted locally, alerts on missing backups, just a breeze to use, and works for my personal machines just like my VPS.
I use the macOS version and it's excellent.
I use B2 for cloud, and two NAS boxes on my network. I used to use OneDricd thanks to a legacy plan that was generous, but that appears to have stopped working for unknown reasons.
All data is encrypted with a paraphrase I supply, so short of some spectacular amount of brute force I consider it safe.
What I backup: Three machines currently, my laptop, my desktop, and my wife's laptop. I don't do a full drive backup as I have no problem re-installing software, losing settings, etc. I just backup documents and media for the most part. This includes wedding photos, rental agreements, bank statements, my own git repos, etc.
All of the photos and most documents also sit in a dropbox folder and are downloaded across all 3 machines. We don't do every photo from our phones because we take a lot of rubbish but usually pull over holiday snaps etc pretty quickly.
When I backup: Each machine has a daily backup using Arq which goes up to AWS S3. I then have weekly backups to Backblaze B2. Only reason to not have daily going to B2 is just to keep costs low. This backup frequency feels comfortable for our uses and we feel fairly comfortable with photos being on dropbox and synced in real-time as those are the most important to us.
I also have a separate backup from my wife's computer which runs hourly and just stores documents related to her studying to minimise loss of work if the laptop crashed during the day.
All in all this costs about $3-$5 a month on AWS and a bit less for Backblaze B2. We then pay for dropbox individual plus at £95 a year. All the backups are compressed and encrypted by Arq and it rolls up and ages off backups for us as I don't really care too much about recovering something from several years ago. Looking at the S3 dashboard we're storing 168.3 GB in total across 4 buckets.
I'm sure many people will say this is insanely little data to backup, but it's not important to us to backup everything really, we'd rather have a simple and cheap system to backup the data that's important to us. With the prices I'd have no problem expanding it to more data if needed though.
In the future I'll probably look at buying a NAS and hooking it up to Arq as well, but that'll have to wait until we've bought our first house.
Final note of praise for Arq, UI is really simple (my wife who's not a techie understands it), you can setup email alerts, and recover individual documents from specific backups without needing to restore everything.