Proton, provider of various privacy-focused online services, announced that its end-to-end encrypted cloud storage service, known as Proton Drive, is now available on mobile devices, according to TechCrunch. Launched on the web back in September, the service provides zero-knowledge encrypted cloud storage and file-sharing, which means data cannot be intercepted at any point in the process by parties other than the sender and the recipient. Proton says its service can be used in sharing files and folders with non-Proton Drive users through secure links that the sender can secure with passwords, expiration dates and a manual revocation option. The company also touts that it owns all of its infrastructure and does not rely on third parties and promotes transparency by making all of its apps open-source. What really sets Proton Drive apart is the rigorous level of encryption -- true end-to-end encryption of not just files and folder, but also filenames, extensions and most other file metadata, and data verification via digital signatures, noted Proton co-founder and CEO Andy Yen.