Cryptomator - Multi-platform transparent client-side encryption of your files in the cloud

Cryptomator offers multi-platform transparent client-side encryption of your files in the cloud. Most cloud providers encrypt data only during transmission or they keep the keys for decryption for themselves. These keys can be stolen, copied, or misused. With Cryptomator, the key to your data is in your hands. Cryptomator encrypts your data quickly and easily. Afterwards you upload them protected to your favorite cloud service.

It works with Dropbox, Google Drive, OneDrive, MEGA, pCloud, ownCloud, Nextcloud and any other cloud storage service which synchronizes with a local directory. It uses AES encryption with 256-bit key length.