Partly security, mostly privacy.
It’s not for anything particularly top secret or dodgy. It’s mainly because using ‘cloud sync/storage/backup’ services like Google Drive, Onedrive, Dropbox is very handy, but I’m also not keen on having them looking through my documents and photos.
We had a smartphone sd card die on us a year or so back, and had no backups of those photos because my other half wasn’t keen on the idea of uploading them to Google Drive for privacy reasons.
ToS vary depending on the service, but most of them you’re granting them some ability to look through your files. I have a grandfathered 25Gb Onedrive account that would be very hand to use for photos, but Onedrive have been known to use automated software to scan all photos for illegal ones, and then have staff review anything that gets flagged.
I won’t have any illegal photos, but I’m still not keen on MS staff checking pics of my kids, etc…
I imagine Google Drive does something similar, if only for ads.
The theoretical idea with Cryptomator would be that you could continue to use Onedrive, Google Drive etc… as usual, but everything would get automatically and seamlessly encrypted and decrypted on upload and download, so only you’d have access to the contents.
What I’m not sure of is how ‘seamless’ it actually is. I imagine it’d work ok on PC, and that software is free to download so I could try, but I worry about the smartphone version taking 5 minutes to encrypt each picture, or burning through battery or something.
There’s no free mobile version to try, so I just wondered if anyone had any hands on experience.
I wasn’t really thinking of using it for sharing with other people, or for local encryption, just for using those cloud services without the downsides.