Cryptomator provides transparent, client-side encryption for your cloud. The software provides a virtual hard drive through which you can access your files. Protect your documents on Dropbox, Google Drive etc. from unauthorized access. Cryptomator is free and open source software.
Cryptomator encrypts file contents and names using AES. Your passphrase is protected against bruteforcing attempts using scrypt. Directory structures get obfuscated. The only thing which cannot be encrypted without breaking your cloud synchronization is the modification date of your files.
Compared to other disk encryption utilities, Cryptomator encrypts each file individually. So if you edit just a small text file, only the corresponding encrypted file is changed.
The software works with Dropbox, Google Drive, OneDrive, ownCloud, Nextcloud and any other cloud storage service which synchronizes with a local directory.
Cryptomator features include AES encryption with 256-bit key length, folder structure gets obfuscated, file names get encrypted, use as many vaults in your Dropbox as you want, each having individual passwords, client side - no accounts, no data shared with any online service.