Cryptomator

It provides client‑side, transparent encryption for files stored in cloud services such as Dropbox, Google Drive, OneDrive, iCloud Drive, SharePoint, pCloud, Nextcloud and others. Users create a password‑protected “vault” inside their cloud folder; the vault is presented as a virtual drive where files are automatically encrypted with AES‑256 for both data and filenames. No registration, key‑management server, or additional configuration is required, and the encrypted data can be accessed from any device that runs the software.

The tool is open‑source and free, with its code publicly available for inspection and independent security audits. Audits and automated testing are cited as evidence of high code quality and test coverage, and the project claims compliance with GDPR requirements for personal data handling. Because the encryption keys never leave the user’s device, the cloud provider cannot decrypt the stored content.

It is positioned for individuals and teams who want to protect the confidentiality of their cloud‑stored files without relying on the provider’s own encryption mechanisms. The software runs on multiple platforms, offering a consistent workflow for creating, mounting, and using encrypted vaults across desktop and mobile environments.