Secure and trustworthy file sharing over cloud storage using eID tokens
This work addresses secure file sharing for users of existing cloud services, but it is incremental as it builds on standard cryptographic and eID methods without introducing new paradigms.
The paper tackles the problem of securing data in cloud storage by developing a multi-platform application that uses national eID tokens for authentication and cloud storage for cryptographic material exchange, successfully tested across multiple operating systems and cloud providers.
This paper presents a multi-platform, open-source application that aims to protect data stored and shared in existing cloud storage services. The access to the cryptographic material used to protect data is implemented using the identification and authentication functionalities of national electronic identity (eID) tokens. All peer to peer dialogs to exchange cryptographic material is implemented using the cloud storage facilities. Furthermore, we have included a set of mechanisms to prevent files from being permanently lost or damaged due to concurrent modification, deletion and malicious tampering. We have implemented a prototype in Java that is agnostic relatively to cloud storage providers; it only manages local folders, one of them being the local image of a cloud folder. We have successfully tested our prototype in Windows, Mac OS X and Linux, with Dropbox, OneDrive, Google Drive and SugarSync.