TwinCloud: secure cloud sharing without explicit key management

In this paper, we propose TwinCloud as a client-side solution providing a secure system to users without compromising the usability of cloud sharing. TwinCloud brings a novel solution to the complex key exchange problem and provides a simple and practical approach to store and share files by hiding all the cryptographic and key-distribution operations from users. Serving as a gateway, TwinCloud stores the encryption keys and encrypted files in separate clouds which ease the secure sharing without a need for trust to either of the cloud service providers with the assumption that they do not collude with each other. TwinCloud is a lightweight application and available as open-source.