Cryptomator

Cryptomator is an open-source client-side encryption tool that creates encrypted vaults on your local drive, which you can then sync to ANY cloud service (Dropbox, Google Drive, etc.). It provides transparent, zero-knowledge encryption, making an insecure cloud secure.

It works by creating a virtual drive for your vault. It's a one-time purchase per platform. It ranks as a powerful, flexible solution for users who want to keep their current cloud provider but add a strong layer of privacy and security, democratizing end-to-end encryption across all storage platforms.